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# Symmetry Breaking

11.08.2022
18:30 Mechanisms for Spontaneous Symmetry Breaking in Developing Visual Cortex

Author(s): Francesco Fumarola, Bettina Hein, and Kenneth D. MillerScientists may have answered a longstanding question in biophysics: how the brain learns to recognize features in images before a newborn even opens its eyes. [Phys. Rev. X 12, 031024] Published Thu Aug 11, 2022

27.07.2022
17:30 Forced symmetry breaking as a mechanism for rogue bursts in a dissipative nonlinear dynamical lattice

Author(s): P. Subramanian, E. Knobloch, and P. G. KevrekidisA ring of coupled oscillators can form rogue waves, large-amplitude bursts that are localized in space and time. This paper provides an alternative mechanism for the formation of rogue waves in a dissipative nonlinear lattice system, and describes the effect of varying the coupling strength. [Phys. Rev. E 106, 014212] Published Wed Jul 27, 2022

09.02.2022
19:54 Time-reversal symmetry-breaking charge order in a kagome superconductor

07.02.2022
23:24 Teams collaborate to reach a better understanding of symmetry breaking

In an international collaboration, AMOLF researchers have theoretically described and experimentally observed spontaneous symmetry breaking (SSB) in two laser-driven coupled optical cavities. SSB is a universal phenomenon that occurs in many physical systems. It is at the heart of the laser, superconductivity, and the Higgs mechanism, for example. In the case of laser-driven systems like optical cavities, it was not yet understood how SSB occurs. Because laser-driven systems are always in a state imposed by the laser, the nature and manifestation of SSB is completely different from other systems.

13.01.2022
23:44 Study reveals how to break symmetry in colloidal crystals

Nature keeps a few secrets. While plenty of structures with low symmetry are found in nature, scientists have been confined to high-symmetry designs when synthesizing colloidal crystals, a valuable type of nanomaterial used for chemical and biological sensing and optoelectronic devices.

22:57 Study reveals how to break symmetry in colloidal crystals

New strategy uses electron equivalents to create the first rules for synthesizing low-symmetry colloidal crystals, including structures never found in nature.

06.01.2022
18:44 Evidence of a quantum phase transition without symmetry breaking in cerium-cobalt-indium 5

Over the past few decades, many condensed matter physicists have conducted research focusing on quantum phase transitions that are not clearly associated with a broken symmetry. One reason that these transitions are interesting is that they might underpin the mechanism of high-temperature superconductivity.

30.11.2021
11:04 Breaking the symmetry of sound waves allows the sound to be directed to a certain place

Research undertaken by the Universidad Carlos III de Madrid (UC3M) has concluded that sound can be directed to

29.11.2021
20:39 Breaking the symmetry of sound waves allows the sound to be directed to a certain place

Research undertaken by the Universidad Carlos III de Madrid (UC3M) has concluded that sound can be directed to a certain place if the sound waves' symmetry is broken. In order to carry out this work, recently published in the journal Nature, researchers used the whispering gallery phenomenon, a circular, vaulted room in which you can hear what is being said in a specific part of the room from anywhere, even if it is being whispered.

12.11.2021
18:54 Existence of Replica-Symmetry Breaking in Quantum Glasses

Author(s): Hajo Leschke, Chokri Manai, Rainer Ruder, and Simone WarzelA rigorous proof shows for the first time that the replica-symmetry-breaking phase is not immediately destroyed by adding a finite transverse field to a Sherrington-Kirkpatrick model. [Phys. Rev. Lett. 127, 207204] Published Fri Nov 12, 2021

18.10.2021
19:27 Researchers observe translation symmetry breaking in twisted bilayer graphene

Magic-angle twisted bilayer graphene is a material made of two sheets of graphene placed on top of each other, with one sheet twisted at precisely 1.05 degrees with respect to the other. This material has been found to be a very promising platform for studying different phases of matter, as it combines metallic, superconducting, magnetic and insulating phases in a single crystal.

19:16 mRNA degradation induced by fluid flow breaks left–right symmetry in vertebrates

A better knowledge of the causes of disease, birth defects and genetic syndromes could come from new insights gleaned by RIKEN biologists into how mice embryos develop asymmetry between their left and right sides.

23.09.2021
17:54 Spontaneous symmetry breaking and frustrated phases

Author(s): Heitor Casasola, Carlos A. Hernaski, Pedro R. S. Gomes, and Paula F. BienzobazFrustrated spin systems exhibit rich physical properties, and this paper presents an exactly solvable example of a frustrated system of quantum spins on a lattice. The authors analyze several quantum phase transitions, characterize the phases, and discuss the mechanism leading to the phase transitions. [Phys. Rev. E 104, 034131] Published Thu Sep 23, 2021

09.09.2021
18:02 Symmetry breaking in electron-impact dissociative ionization of linear symmetric molecules

Author(s): Noboru Watanabe and Masahiko TakahashiThe authors report experimental measurements on electron-impact ionization of CO 2 using the angle- and energy-resolved electron-ion-coincidence technique. The results provide experimental evidence of symmetry breaking in electron-impact dissociative ionization of symmetric molecules. [Phys. Rev. A 104, 032812] Published Thu Sep 09, 2021

30.07.2021
17:57 Testing isospin symmetry breaking in

Author(s): M. S. Martin, S. R. Stroberg, J. D. Holt, and K. G. LeachSuperallowed β decay, resulting when near-exact isospin symmetry exists between the initial and final nuclei, is an important test of the Standard Model. Understanding the minute breaking of isospin in such nuclei is thus crucially important. The authors calculate signatures of isospin breaking in all relevant superallowed systems, starting from underlying two- and three-nucleon forces. While their results agree with experiment, simpler phenomenological models reproduce these effects more accurately, showing that work remains to be done. [Phys. Rev. C 104, 014324] Published Fri Jul 30, 2021

27.07.2021
19:54 Inhomogeneous time-reversal symmetry breaking in ${\mathrm{Sr}}_{2}{\mathrm{RuO}}_{4}$

Author(s): Roland Willa, Matthias Hecker, Rafael M. Fernandes, and Jörg SchmalianThis work provides compelling evidence that time-reversal symmetry breaking (TRSB) in the superconducting phase of Sr 2 RuO 4 is due to inhomogeneous strain. Specifically, it demonstrates that strong inhomogeneous strain near crystallographic dislocations can promote a subleading superconducting state and thereby induce local TRSB in an otherwise single-component d -wave superconductor. The winding of the relative phase between the two superconducting condensates near dislocations,

18.06.2021
15:48 Breaking 2D Material's Symmetry can Create a Novel Optoelectronic Phenomenon

Optoelectronic materials that are capable of converting the energy of light into electricity, and electricity into light, have promising applications as light-emitting, energy-harvesting, and sensing...

10.06.2021
18:34 Mystery object caused by spontaneous symmetry breaking revealed

Hiromitsu Takeuchi, a lecturer at the Graduate School of Science, Osaka City University, and a researcher at the Nambu Yoichiro Institute of Theoretical and Experimental Physics (NITEP), has theoretically identified the nature of a mysterious topological defect produced by the recently discovered non-equilibrium time evolution of spontaneous symmetry breaking (SSB). Since the SSB realized in this system is like the SSB that has been known to occur in isotropic superconductors and superfluid 4He, it was expected to produce topological defects with vortex-like properties in the fluid, called quantum vortices. However, the topological defect observed in this experiment has a structure that bore little resemblance to the previously mentioned SSB, and its physical properties have been shrouded in mystery. In this research, the idea of applying the Joukowski transform, which is used to calculate the lift of airplane wings, to quantum vortices was introduced for the first time, and the

19.05.2021
18:53 Viewpoint: Shining a Light on Chiral Symmetry Breaking in Graphene

Author(s): Christopher GutiérrezSensitive photoemission measurements visualize the signatures of a symmetry-broken phase of graphene with carriers of mixed handedness. [Physics 14, 76] Published Wed May 19, 2021

17:54 Experimental Evidence of Chiral Symmetry Breaking in Kekulé-Ordered Graphene

Author(s): Changhua Bao, Hongyun Zhang, Teng Zhang, Xi Wu, Laipeng Luo, Shaohua Zhou, Qian Li, Yanhui Hou, Wei Yao, Liwei Liu, Pu Yu, Jia Li, Wenhui Duan, Hong Yao, Yeliang Wang, and Shuyun ZhouSensitive photoemission measurements visualize the signatures of a symmetry-broken phase of graphene with carriers of mixed handedness. [Phys. Rev. Lett. 126, 206804] Published Wed May 19, 2021

17:54 Spontaneous Time-Reversal Symmetry Breaking at Individual Grain Boundaries in Graphene

Author(s): Kimberly Hsieh, Vidya Kochat, Tathagata Biswas, Chandra Sekhar Tiwary, Abhishek Mishra, Gopalakrishnan Ramalingam, Aditya Jayaraman, Kamanio Chattopadhyay, Srinivasan Raghavan, Manish Jain, and Arindam GhoshQuantum transport and universal conductance fluctuation measurements show spontaneous breaking of time-reversal symmetry across graphene grain boundaries. [Phys. Rev. Lett. 126, 206803] Published Wed May 19, 2021

20.01.2021
18:56 Spin-polarized quantized electronic structure of Fe(001) with symmetry breaking due to the magnetization direction

Author(s): E. Młyńczak, I. Aguilera, P. Gospodarič, T. Heider, M. Jugovac, G. Zamborlini, C. Tusche, S. Suga, V. Feyer, S. Blügel, L. Plucinski, and C. M. SchneiderQuantum well states are responsible for many fundamental phenomena that oscillate with layer thickness, such as magnetic anisotropy or magnetoresistance. Here, the authors present the magnetization-dependent quantized electronic states of Fe(001), mapped in unprecedented detail using spin-resolved momentum microscopy and high-resolution angle-resolved photoemission. The experimental observations are compared with photoemission simulations, based on the bulk initial electronic band structure, which include quantization of the initial states and broadening of the final states along the wave vector direction perpendicular to the sample surface. [Phys. Rev. B 103, 035134] Published Wed Jan 20,

09.11.2020
19:02 Symmetry breaking in binary Bose-Einstein condensates in the presence of an inhomogeneous artificial gauge field

Author(s): S. Sahar S. Hejazi, Juan Polo, Rashi Sachdeva, and Thomas BuschThe ground state of interacting two-component Bose-Einstein condensates in the presence of an inhomogeneous artificial gauge potential is found to exhibit symmetry breaking in the phase separated regime. This theoretical work explains that this behavior arises as a consequence of the competition between the interaction and the rotational energies.” [Phys. Rev. A 102, 053309] Published Mon Nov 09, 2020

15.10.2020
14:09 Study examines spontaneous symmetry breaking in twisted double bilayer graphene

Over the past few years, a growing number of researchers worldwide has been conducting studies investigating the properties and features of so-called twisted van der Waals (vdW) materials. This unique class of materials could be an ideal platform to examine correlated phases that occur as a result of strong interactions between electrons.

04.09.2020
16:22 Squaring the circle—Breaking the symmetry of a sphere to control the polarization of light

Scientists at Tokyo Institute of Technology and Institute of Photonic Sciences have developed a method to generate circularly polarized light from the ultimate symmetrical structure: the sphere. Their approach involves breaking the inherent symmetry of the sphere by electron beam excitation, which allows for precisely controlling the phase and polarization of the emitted light. This method can be used to encode information in the phase and polarization direction of circularly polarized light, enabling novel quantum communication and encryption technologies.

11:23 Squaring the circle - Breaking the symmetry of a sphere to control the polarization of light

Scientists developed a method to generate circularly polarized light from the ultimate symmetrical structure: the sphere. Their approach involves breaking the inherent symmetry of the sphere by electron beam excitation, which allows for precisely controlling the phase and polarization of the emitted light.

25.08.2020
18:41 Time-reversal symmetry breaking versus chiral symmetry breaking in twisted bilayer graphene

Author(s): J. González and T. StauberDynamical symmetry breaking is a mechanism by which a strong Coulomb interaction can give mass and open a gap in the spectrum of Dirac-like quasiparticles. The authors demonstrate that the large interaction strength in twisted bilayer graphene leads actually to a competition between the breakdown of chiral symmetry and time-reversal symmetry, with a gap being generated by the Dirac and the Haldane masses, respectively. They find quite an abrupt transition between the two phases, indicating the existence of a quantum critical point at the magic angle of twisted bilayer graphene. [Phys. Rev. B 102, 081118(R)] Published Tue Aug 25, 2020

17.07.2020
19:05 Time-reversal symmetry breaking in the noncentrosymmetric ${\mathrm{Zr}}_{3}\mathrm{Ir}$ superconductor

Author(s): T. Shang, S. K. Ghosh, J. Z. Zhao, L.-J. Chang, C. Baines, M. K. Lee, D. J. Gawryluk, M. Shi, M. Medarde, J. Quintanilla, and T. ShirokaThe Zr 3 Ir superconductor exhibits the coexistence of two exotic, and normally distinct, features: mixed singlet-triplet pairing and broken time-reversal symmetry. Mixed singlet-triplet pairing can take place in superconductors whose crystal lattices lack inversion symmetry. This relativistic effect, which does not require the breaking of additional symmetries, nor an unconventional pairing mechanism, is often quite small. Broken time-reversal symmetry, on the other hand, means that the superconducting state is magnetic and necessitates an unconventional pairing mechanism. The coexistence of these two

05.06.2020
17:37 Breaking symmetry leads to responsive organic photodetectors

A column of liquid crystal molecules could form the basis of a new breed of flexible light detectors that have ultrafast responses, an all-RIKEN team has demonstrated.

07:41 Breaking symmetry leads to responsive organic photodetectors

A response to light usually seen only in inorganic compounds has been realized in organic liquid crystals, opening the way to highly responsive photodetectors.

02.06.2020
17:20 Searching for new sources of matter–antimatter symmetry breaking in Higgs boson interaction with top quarks

When a particle is transformed into its antiparticle and its spatial coordinates inverted, the laws of physics are required to stay the same—or so we thought. This symmetry—known as CP symmetry (charge conjugation and parity symmetry) – was considered to be exact until 1964, when a study of the kaon particle system led to the discovery of CP violation.

15:46 Researchers discover symmetry-breaking phase transitions after isotopic doping

A joint team, while exploring phase diagrams in dense H2–HD–D2 mixtures, has reported a new discovery in which they found counterintuitive effects of isotopic doping on the phase diagram of H2–HD–D2 molecular alloy.

20.05.2020
17:00 Electrons break rotational symmetry in exotic low-temp superconductor

This odd behavior may promote the material's ability upon cooling to perfectly conduct electricity in a way unexplained by standard theories.

07:52 Electrons Break Rotational Symmetry in Exotic Low-Temp Superconductor

Scientists previously observed this peculiar behavior—characterized by electrons preferentially traveling along one direction, decoupled from the host crystal

19.05.2020
18:05 Electrons break rotational symmetry in exotic low-temp superconductor

Scientists have discovered that the transport of electronic charge in a metallic superconductor containing strontium, ruthenium, and oxygen breaks the rotational symmetry of the underlying crystal lattice. The strontium ruthenate crystal has fourfold rotational symmetry like a square, meaning that it looks identical when turned by 90 degrees (four times to equal a complete 360-degree rotation). However, the electrical resistivity has twofold (180-degree) rotational symmetry like a rectangle.

18.05.2020
22:04 Simultaneous Nodal Superconductivity and Time-Reversal Symmetry Breaking in the Noncentrosymmetric Superconductor CaPtAs

Author(s): T. Shang, M. Smidman, A. Wang, L.-J. Chang, C. Baines, M. K. Lee, Z. Y. Nie, G. M. Pang, W. Xie, W. B. Jiang, M. Shi, M. Medarde, T. Shiroka, and H. Q. YuanCaPtAs provides a link between correlated magnetic and weakly-correlated noncentrosymmetric superconductors, the latter of which usually exhibit only fully gapped behavior. [Phys. Rev. Lett. 124, 207001] Published Mon May 18, 2020

01.04.2020
18:56 NUS Scientists Invent Symmetry-Breaking In A Nanoscale Device That Can Mimic Human Brain

Over the last decade, artificial intelligence (AI) and its applications such as machine learning have gained pace to revolutionise many industries. As the world gathers more data, the computing power...

24.03.2020
17:11 Scientists invent symmetry-breaking for the first time in a nanoscale device that can mimic human brain

Over the last decade, artificial intelligence (AI) and its applications such as machine learning have gained pace to revolutionize many industries. As the world gathers more data, the computing power of hardware systems needs to grow in tandem. Unfortunately, we are facing a future where we will not be able to generate enough energy to power our computational needs.

28.02.2020
20:25 Reconfigurable chiral microlaser by spontaneous symmetry breaking

Coherent light sources are one of the most crucial foundations in both scientific disciplines and advanced applications. As a prominent platform, ultrahigh-Q whispering-gallery mode (WGM) microcavities have witnessed significant developments of novel light sources. However, the intrinsic chiral symmetry of WGM microcavity geometry and the resulting equivalence between the two directions of laser propagation in a cavity severely limits further applications of microlasers.

02.01.2020
18:35 Transient Second-Order Nonlinear Media: Breaking the Spatial Symmetry in the Time Domain via Hot-Electron Transfer

Author(s): Mohammad Taghinejad, Zihao Xu, Kyu-Tae Lee, Tianquan Lian, and Wenshan CaiUsing a laser, researchers double the frequency of light reflected off a surface, showcasing on-demand, all-optical control of optical effects needed in optoelectronics. [Phys. Rev. Lett. 124, 013901] Published Thu Jan 02, 2020

22.11.2019
00:28 Breaking (and restoring) graphene's symmetry in a twistable electronics device

A recent study from the labs of James Hone (mechanical engineering) and Cory Dean (physics) demonstrates a new way to tune the properties of two-dimensional (2-D) materials simply by adjusting the twist angle between them. The researchers built devices consisting of monolayer graphene encapsulated between two crystals of boron nitride and, by adjusting the relative twist angle between the layers, they were able to create multiple moiré patterns.

00:04 Breaking (and restoring) graphene's symmetry in a twistable electronics device

Researchers invent a new way to tune the properties of 2D materials by adjusting the twist angle between them; technology enables the development of nanoelectromechanical sensors with applications in astronomy, medicine, search and rescue, and more.

21.11.2019
22:45 Breaking (and restoring) graphene's symmetry in a twistable electronics device

A recent study demonstrates a new way to tune the properties of 2D materials simply by adjusting the twist angle between them. The researchers built devices consisting of monolayer graphene encapsulated between two crystals of boron nitride and, by adjusting the relative twist angle between the layers, they were able to create multiple moiré pattern--''the first time anyone has seen the full rotational dependence of coexisting moiré superlattices in one device.''

10.09.2019
17:44 Magnetic frustration and spontaneous rotational symmetry breaking in ${\mathrm{PdCrO}}_{2}$

Author(s): Dan Sun, Dmitry A. Sokolov, Jack M. Bartlett, Jhuma Sannigrahi, Seunghyun Khim, Pallavi Kushwaha, Dmitry D. Khalyavin, Pascal Manuel, Alexandra S. Gibbs, Hidenori Takagi, Andrew P. Mackenzie, and Clifford W. HicksIn the delafossite lattice structure of the triangular antiferromagnet PdCrO 2 , the interlayer stacking means that the net interlayer exchange interaction is zero. Through neutron scattering measurements under uniaxial stress, the authors show here that magnetism relieves this frustration through a spontaneous tilt of the spins that breaks the threefold rotational symmetry of the nonmagnetic lattice. It is also demonstrated through resistivity measurements that uniaxial stress can suppress thermal magnetic fluctuations within the

09.09.2019
18:21 Supersolid symmetry breaking from compressional oscillations in a dipolar quantum gas

06.09.2019
17:39 Background-Free Measurement of Ring Currents by Symmetry-Breaking High-Harmonic Spectroscopy

Author(s): Ofer Neufeld and Oren CohenA technique based on high harmonic generation is proposed to probe and characterize electric currents in excited atomic and molecular media. [Phys. Rev. Lett. 123, 103202] Published Fri Sep 06, 2019

29.08.2019
15:06 Break in temporal symmetry produces molecules that can encode information

In a study published in Scientific Reports, a group of researchers affiliated with São Paulo State University (UNESP) in Brazil describes an important theoretical finding that may contribute to the development of quantum computing and spintronics (spin electronics), an emerging technology that uses electron spin or angular momentum rather than electron charge to build faster, more efficient devices.

09.08.2019
23:50 Ultracold quantum particles break classical symmetry

Many phenomena of the natural world evidence symmetries in their dynamic evolution which help researchers to better understand a system's inner mechanism. In quantum physics, however, these symmetries are not always achieved. In laboratory experiments with ultracold lithium atoms, researchers have shown for the first time the theoretically predicted deviation from classical symmetry.

20:12 Ultracold quantum particles break classical symmetry

Many phenomena of the natural world evidence symmetries in their dynamic evolution which help researchers to better understand a system's inner mechanism. In quantum physics, however, these symmetries are not always achieved. In laboratory experiments with ultracold lithium atoms, researchers from the Center for Quantum Dynamics at Heidelberg University have proven for the first time the theoretically predicted deviation from classical symmetry. Their results were published in the journal Science.

06.08.2019
14:25 New milestone reached in the study of electroweak symmetry breaking

In the Standard Model of particle physics, elementary particles acquire their masses by interacting with the Higgs field. This process is governed by a delicate mechanism: electroweak symmetry breaking (EWSB). Although EWSB was first proposed in 1964, it remains among the least understood phenomena of the Standard Model as a large dataset of high-energy particle collisions is required to probe it.

25.07.2019
18:23 Large deviations in models of growing clusters with symmetry-breaking transitions

Author(s): Robert L. JackNonequilibrium systems are ubiquitous in nature but many of their properties are still poorly understood. In this work, the author provides an insightful look at this problem by examining large-deviation theory for reversible and irreversible models of growth. [Phys. Rev. E 100, 012140] Published Thu Jul 25, 2019

14.06.2019
20:48 Breaks in the perfect symmetry of the universe could be a window into completely new physics

The bible of particle physics is dying for an upgrade. And physicists may have just the thing: Some particles and forces might look in the mirror and not recognize themselves. That, in itself, would send the so-called Standard Model into a tailspin.

14:19 Breaks in the Perfect Symmetry of the Universe Could Be a Window Into Completely New Physics

If this fundamental symmetry of the universe doesn’t hold, it could break open new physics.

03.06.2019
14:05 Breaking the symmetry in the quantum realm

For the first time, researchers have observed a break in a single quantum system. The observation—and how they made the observation—has potential implications for physics beyond the standard understanding of how quantum particles interact to produce matter and allow the world to function as we know it.

06.05.2019
15:25 Emergence and spontaneous breaking of approximate $\mathrm{O}(4)$ symmetry at a weakly first-order deconfined phase transition

Author(s): Pablo Serna and Adam NahumAn unusual phenomenology is uncovered in a class of (2+1)-dimensional phase transitions. An accurate, yet not exact O(4) symmetry, relating distinct order parameters, emerges at intermediate length scales. At longer scales it becomes apparent that the transition is weakly first order. However, O(4) persists as a symmetry relating the coexisting ground states, implying very unconventional scaling properties. The transition studied is from Naposeel order to a twofold degenerate valence-bond solid. Via dualities, the results have implications for other deconfined critical points with four soft-order parameter components and for two-flavor QED 3 . [Phys. Rev. B 99, 195110] Published Mon May 06, 2019

24.04.2019
20:05 Self-organization and symmetry breaking in intestinal organoid development

21.11.2018
17:16 New device for symmetry-breaking-induced optical nonlinearity

Second-order nonlinear optical processes play a pivotal role in both classical and quantum applications, ranging from extension of the accessible frequencies to generation of quantum entangled photon pairs and squeezed states. This nonlinearity is ruled out, unfortunately, by inversion symmetry in materials lying at the heart of integrated photonics, for example, silica, silicon and silicon nitride.

15.10.2018
18:10 Emergent Dirac Gullies and Gully-Symmetry-Breaking Quantum Hall States in $ABA$ Trilayer Graphene

Author(s): A. A. Zibrov, P. Rao, C. Kometter, E. M. Spanton, J. I. A. Li, Cory R. Dean, T. Taniguchi, K. Watanabe, M. Serbyn, and A. F. YoungResearchers observe new features in the band structure of multilayer graphene that point to enhanced electron interactions. [Phys. Rev. Lett. 121, 167601] Published Mon Oct 15, 2018

20.09.2018
14:38 Quantum anomaly—breaking a classical symmetry with ultracold atoms

A FLEET study of ultracold atomic gases—a billionth the temperature of outer space—has unlocked new, fundamental quantum effects. The researchers at Swinburne University of Technology studied collective oscillations in ultracold atomic gases, identifying where quantum effects occur to break symmetries predicted by classical physics. They also observed the transition between two-dimensional (2-D) behaviour and three-dimensional (3-D) behaviour.

19.09.2018
21:58 Quantum anomaly: Breaking a classical symmetry with ultracold atoms

A new study of ultracold atomic gases finds a quantum anomaly: strongly interacting particles breaking classical symmetry in a 2-D Fermi gas.

17.09.2018
17:06 Breaking the symmetry between fundamental forces

A fraction of a second after the Big Bang, a single unified force may have shattered. Scientists from the CDF and DZero Collaborations used data from the Fermilab Tevatron Collider to re-create the early universe conditions. They measured the weak mixing angle that controls the breaking of the unified force. Measuring this angle, a key parameter of the standard model, improves our understanding of the universe. The details of this symmetry breaking affect the nature of stars, atoms, and quarks. The new measurement of the weak mixing angle helps cement our understanding of the past, the character of what we observe today, and what we believe is in store for our future.

13.09.2018
14:26 Physicists revealed spontaneous T-symmetry breaking and exceptional points in cavity QED

Spontaneous symmetry breaking (SSB) is a physics phenomenon in which a symmetric system produces symmetry-violating states. Recently, extensive study shows that the parity-time symmetry breaking in open systems leads to exceptional points, promising for novel applications leasers and sensing.

07.09.2018
15:37 Origin of symmetry breaking in the seed-mediated growth of bimetal nano-heterostructures

During seed-mediated growth, the Pd-Au nano-heterostructure can be either centrosymmetric Pd@Au core-shell trisoctahedra or asymmetric Pd-Au heterodimers. What causes the symmetry breaking of bimetal nano-heterostructures? A recent study proposes that the thermodynamic factor plays a key role for the symmetry breaking of bimetal nano-heterostructures during seed-mediated growth.

07.08.2018
18:05 Symmetry breaking and unconventional charge ordering in single crystal ${\mathrm{Na}}_{2.7}{\mathrm{Ru}}_{4}{\mathrm{O}}_{9}$

Author(s): Arvind Yogi, C. I. Sathish, Hasung Sim, Matthew J. Coak, Y. Noda, and Je-Geun ParkSynthesis of complex materials can lead to discoveries of novel emergent phenomena as well as innovative applications. Combined electrical resistivity, specific heat, susceptibility, and single-crystal x-ray diffraction studies reveal that Na 2 . 7 Ru 4 O 9 undergoes a unique unconventional charge-ordering transition at room temperature while retaining metallicity. This electronic transition

28.05.2018
14:06 Physicists invent flux capacitor, break time-reversal symmetry

In the popular movie franchise "Back to the Future", an eccentric scientist creates a time machine that runs on a flux capacitor.

08:23 Physicists invent flux capacitor to break time-reversal symmetry

Physicists have invented a flux capacitor and, while it might not run a ‘Back to the Future’ inspired

22.02.2018
21:55 New symmetry-breaking method opens way for bioactive compounds

Chemists have developed a new catalytic method for symmetry breaking. The method can help synthesize important building blocks for bioactive compounds such as anticancer drugs.

20:28 New symmetry-breaking method opens way for bioactive compounds

Many chemical molecules can exist in nature together with their mirror counterparts; like hands, two compounds can be made up of the same atoms in the same overall structure but in opposite orientations, i.e. left-handed and right-handed. This phenomenon of symmetry is called "chirality", and can give mirror counterparts ("enantiomers") entirely different chemical properties. A famous and tragic example of chirality is thalidomide, which was originally sold as a mixture of both enantiomers. The problem was that one was a harmless sedative and the other highly toxic to fetuses, resulting in disturbing congenital deformities.

14.02.2018
14:39 Breaking local symmetry—why water freezes but silica forms a glass

Everyone knows that water freezes at 0 degrees C. Life on Earth would be vastly different if this were not so. However, water's cousin, silica, exhibits wayward behavior when cooled that has long puzzled scientists.

01:05 Breaking local symmetry: Why water freezes but silica forms a glass

Researchers have simulated water and silica at low temperature. Despite structural similarities, the two liquids act differently when they are cooled: water freezes into ice, while silica continues to supercool, and eventually forms a glass. This arises from poor symmetry-breaking in silica; although atoms arrange properly in the first shell in both liquids, local rotational symmetry is harder to break in the second shell in silica, because of the less directional Si-O bonds.

05.02.2018
19:37 Symmetry breaking and the fermionic fractional Chern insulator in topologically trivial bands

Author(s): Stefanos KourtisSubjecting a topologically nontrivial class of noninteracting electronic states to interactions can sometimes yield a “fractional” topologically ordered version of that class. For example, electrons in topological bands with integer-quantized Hall conductivity can generate fractional quantum Hall (FQH) states upon addition of repulsive interactions. However, of all existing material band structures, the topologically nontrivial ones are rare. Here, the author demonstrates theoretically in a minimal setting how strong interactions and symmetry breaking can induce FQH-type topological order even in topologically trivial bands. This finding shows that even topologically trivial band structures – the vast majority – can host topological order. [Phys. Rev. B 97, 085108] Published Mon Feb 05, 2018

06.11.2017
18:29 Breaking cell symmetry

A team of researchers has uncovered a novel mechanism for establishing cell polarity that relies on tension force induced clustering of proteins.

27.09.2017
20:54 Maximal Rashba-like spin splitting via kinetic-energy-coupled inversion-symmetry breaking

Engineering and enhancing the breaking of inversion symmetry in solids—that is, allowing electrons to differentiate between ‘up’ and ‘down’—is a key goal in condensed-matter physics and materials science because it can be used to stabilize states that are of fundamental interest and also have potential practical applications. Examples include improved ferroelectrics for memory devices and materials that host Majorana zero modes for quantum computing. Although inversion symmetry is naturally broken in several crystalline environments, such as at surfaces and interfaces, maximizing the influence of this effect on the electronic states of interest remains a challenge. Here we present a mechanism for realizing a much larger coupling of inversion-symmetry breaking to itinerant surface electrons than is typically achieved. The key element is a pronounced asymmetry of surface hopping energies—that is, a kinetic-energy-coupled inversion-symmetry breaking, the energy scale of which is a

22.09.2017
11:04 Coconut pancakes and the perfect Bloody Mary: Instagram sensation Michael Zee of Symmetry Breakfast on the art of brunch

16.08.2017
21:02 Electronic in-plane symmetry breaking at field-tuned quantum criticality in CeRhIn5

Electronic nematic materials are characterized by a lowered symmetry of the electronic system compared to the underlying lattice, in analogy to the directional alignment without translational order in nematic liquid crystals. Such nematic phases appear in the copper- and iron-based high-temperature superconductors, and their role in establishing superconductivity remains an open question. Nematicity may take an active part, cooperating or competing with superconductivity, or may appear accidentally in such systems. Here we present experimental evidence for a phase of fluctuating nematic character in a heavy-fermion superconductor, CeRhIn5 (ref. 5). We observe a magnetic-field-induced state in the vicinity of a field-tuned antiferromagnetic quantum critical point at Hc ≈ 50 tesla. This phase appears above an out-of-plane critical field H* ≈ 28 tesla and is characterized by a substantial in-plane resistivity anisotropy in the presence of a small in-plane field component. The in-plane

01.08.2017
15:49 Strange Electrons Break the Crystal Symmetry of High-Temperature Superconductors

Brookhaven Lab scientists discover spontaneous voltage perpendicular to applied current that may help unravel the mystery of high-temperature

26.07.2017
22:42 Strange electrons break the crystal symmetry of high-temperature superconductors

Scientists have found surprising electron behavior that may help unravel the ever-elusive mechanism behind high-temperature superconductivity -- a phenomenon in which electrical current flows freely without resistance through a material at unusually high temperatures relative to those of conventional superconductors.

20:42 Spontaneous breaking of rotational symmetry in copper oxide superconductors

The origin of high-temperature superconductivity in copper oxides and the nature of the ‘normal’ state above the critical temperature are widely debated. In underdoped copper oxides, this normal state hosts a pseudogap and other anomalous features; and in the overdoped materials, the standard Bardeen–Cooper–Schrieffer description fails, challenging the idea that the normal state is a simple Fermi liquid. To investigate these questions, we have studied the behaviour of single-crystal La2–xSrxCuO4 films through which an electrical current is being passed. Here we report that a spontaneous voltage develops across the sample, transverse (orthogonal) to the electrical current. The dependence of this voltage on probe current, temperature, in-plane device orientation and doping shows that this behaviour is intrinsic, substantial, robust and present over a broad range of temperature and doping. If the current direction is rotated in-plane by an angle ϕ, the transverse voltage oscillates as

20:01 Strange electrons break the crystal symmetry of high-temperature superconductors

The perfect performance of superconductors could revolutionize everything from grid-scale power infrastructure to consumer electronics, if only they could be coerced into operating above frigid temperatures. Even so-called high-temperature superconductors (HTS) must be chilled to hundreds of degrees Fahrenheit below zero.

12.07.2017
21:34 Interacting nodal-line semimetal: Proximity effect and spontaneous symmetry breaking

Author(s): Bitan RoyThe nodal-line semimetal stands out as a paradigmatic representative of a gapless topological phase of matter that supports linearly dispersing quasiparticles around an isolated closed loop in the bulk and accommodates drumhead shaped surface states. The author demonstrates an intriguing possibility of realizing either charge or spin order on the surface of this system for arbitrarily weak Coulomb repulsion. When onsite Hubbard repulsion dominates, each surface becomes ferromagnetic with its moment pointing in opposite directions on complementary faces, which yields a global antiferromagnet. As shown numerically, surface ordering via proximity effect can in turn induce charge or spin order in the bulk at weak coupling, making the proposed scenario for spontaneous symmetry breaking relevant for materials, such as Ca

01.03.2017
21:34 Supersolid formation in a quantum gas breaking a continuous translational symmetry

The concept of a supersolid state combines the crystallization of a many-body system with dissipationless flow of the atoms from which it is built. This quantum phase requires the breaking of two continuous symmetries: the phase invariance of a superfluid and the continuous translational invariance to form the crystal. Despite having been proposed for helium almost 50 years ago, experimental verification of supersolidity remains elusive. A variant with only discrete translational symmetry breaking on a preimposed lattice structure—the ‘lattice supersolid’—has been realized, based on self-organization of a Bose–Einstein condensate. However, lattice supersolids do not feature the continuous ground-state degeneracy that characterizes the supersolid state as originally proposed. Here we report the realization of a supersolid with continuous translational symmetry breaking along one direction in a quantum gas. The continuous symmetry that is broken emerges from two discrete spatial

25.01.2017
18:40 Symmetry breaking, slow relaxation dynamics, and topological defects at the field-induced helix reorientation in MnSi

Author(s): A. Bauer, A. Chacon, M. Wagner, M. Halder, R. Georgii, A. Rosch, C. Pfleiderer, and M. GarstThe Dzyaloshinskii-Moriya interaction in the cubic chiral magnet MnSi stabilizes a magnetic helix - a periodic one-dimensional modulation of the magnetization. The orientation of this helix is determined by weak magnetocrystalline anisotropies, but it can be reoriented by applying a magnetic field. Here, the authors have studied this reorientation process by means of small-angle neutron scattering and susceptibility measurements. Their results are in excellent agreement with predictions of an effective mean-field theory taking into account the precise symmetries of the crystal structure. Measurements of the magnetization and ac susceptibility provide evidence that the reorientation of helimagnetic domains is associated with large relaxation times

19.01.2017
16:23 Physicists observe spontaneous symmetry breaking in an optical microcavity

Symmetry is the essential basis of nature, which gives rise to conservation laws. In comparison, the breaking of the symmetry is also indispensable for many phase transitions and nonreciprocal processes. Among various symmetry breaking phenomena, spontaneous symmetry breaking lies at the heart of many fascinating and fundamental properties of nature.

09.12.2016
19:24 Golden Probe of Electroweak Symmetry Breaking

Author(s): Yi Chen, Joe Lykken, Maria Spiropulu, Daniel Stolarski, and Roberto Vega-MoralesFour-lepton decays of the Higgs boson could be used to probe a key parameter of electroweak symmetry breaking. [Phys. Rev. Lett. 117, 241801] Published Fri Dec 09, 2016

12.10.2016
17:56 “Symmetry-breaking phase transitions in highly concentrated semen” [study]

21.07.2016
19:13 Curling Liquid Crystal Microswimmers: A Cascade of Spontaneous Symmetry Breaking

Author(s): Carsten Krüger, Gunnar Klös, Christian Bahr, and Corinna C. MaassLiquid-crystal droplets can act like controllable artificial swimmers, twisting in two and three dimensions. [Phys. Rev. Lett. 117, 048003] Published Thu Jul 21, 2016

28.05.2016
17:37 Pedestrian Potential-Collision Standoffs, and Symmetry Breaking

20.05.2016
21:33 Emergence of Long-Range Order in BaTiO_{3} from Local Symmetry-Breaking Distortions

Author(s): M. S. Senn, D. A. Keen, T. C. A. Lucas, J. A. Hriljac, and A. L. GoodwinFerroelectric phase transitions in BaTiO 3 arise from an order-disorder transition with correlated disorder leading to the development of long-range crystallographic order in the material. [Phys. Rev. Lett. 116, 207602] Published Fri May 20, 2016

06.04.2016
05:22 Breaking metamaterial symmetry with reflected light

Researchers have discovered a new type of optical activity by breaking the symmetry of metamaterials with reflected light.

02:06 Breaking metamaterial symmetry with reflected light

Optical activity is well known to occur within materials that differ from their mirror image. But what happens if this symmetry is broken by the direction of illumination rather than the material itself? Curiosity about this has led to the discovery of a new type of optical activity. Breaking the symmetry of metamaterials with reflected light will enable novel applications because it causes optical activity of unprecedented magnitude -- far exceeding previously known specular optical activity.

05.04.2016
18:59 Breaking metamaterial symmetry with reflected light

Optical activity—rotation of the polarization of light—is well known to occur within materials that differ from their mirror image. But what happens if this symmetry is broken by the direction of illumination rather than the material itself?

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