News & Views |
Featured
-
-
Article |
Terahertz field-induced nonlinear coupling of two magnon modes in an antiferromagnet
Magnons—quanta of spin waves—have potential applications in signal processing technology. But it is challenging to obtain coupling between different magnons. Now a study achieves this by demonstrating nonlinear magnon mixing in an antiferromagnet.
- Zhuquan Zhang
- , Frank Y. Gao
- & Keith A. Nelson
-
Article
| Open AccessCorrelated order at the tipping point in the kagome metal CsV3Sb5
The electronic transport properties of charge-ordered kagome metals are controversial. Now careful measurements on unperturbed samples show that previously measured anisotropy in the transport occurs only when external perturbations are present.
- Chunyu Guo
- , Glenn Wagner
- & Philip J. W. Moll
-
News & Views |
Phonons bend to magnetic fields
Phonons do not carry spin or charge, but they can couple to an external magnetic field and cause a sizable transverse thermal gradient. Experiments suggest that phonon handedness is a widespread effect in magnetic insulators with impurities.
- Valentina Martelli
-
Article |
Phonon chirality from impurity scattering in the antiferromagnetic phase of Sr2IrO4
The thermal Hall effect of phonons does not yet have a definitive explanation. Now a careful study of doped Sr2IrO4 suggests that the mechanism involves the scattering of phonons by impurities embedded in an antiferromagnetic environment.
- A. Ataei
- , G. Grissonnanche
- & L. Taillefer
-
Article
| Open AccessThe interplay of field-tunable strongly correlated states in a multi-orbital moiré system
Heterostructures of transition metal dichalcogenides are known to simulate the triangular-lattice Hubbard model. Now, by combining a monolayer and bilayer of different materials, this idea is extended to multi-orbital Hubbard models.
- Aidan J. Campbell
- , Valerio Vitale
- & Brian D. Gerardot
-
Article
| Open AccessPropagation of extended fractures by local nucleation and rapid transverse expansion of crack-front distortion
Understanding the three-dimensional nature of fracture formation and dynamics is challenging. Experiments now show that a fracture front, after originating at a particular locus in a material, propagates jump-wise and expands transversely at high speed.
- T. Cochard
- , I. Svetlizky
- & D. A. Weitz
-
News & Views |
Electronic transport probes a hidden state
Electronic transport measurements of the anomalous Hall effect can probe properties of a frustrated kagome spin ice that are hidden from conventional thermodynamic and magnetic probes.
- Enke Liu
-
Article |
Time reversibility during the ageing of materials
Physical ageing in glassy materials can be described in a linear way through the concept of material time. Multispeckle dynamic light scattering is now shown to provide experimental access to the material time, in terms of which fluctuations become statistically reversible.
- Till Böhmer
- , Jan P. Gabriel
- & Thomas Blochowicz
-
Article |
Tunable quantum simulation of spin models with a two-dimensional ion crystal
Most quantum simulations of spin models with trapped ions have been restricted to one dimension. Now, tunable simulations of Ising models with single-site detection have been demonstrated in two-dimensional ion crystals.
- Mu Qiao
- , Zhengyang Cai
- & Kihwan Kim
-
Article |
Non-Fermi liquid behaviour in a correlated flat-band pyrochlore lattice
Observations of strong electron correlation effects have been mostly confined to compounds containing f orbital electrons. Now, the study of the 3d pyrochlore metal CuV2S4 reveals that similar effects can be induced by flat-band engineering.
- Jianwei Huang
- , Lei Chen
- & Ming Yi
-
News & Views |
Pocket pairs in iron-based materials
Experiments with unprecedented energy and momentum resolution reveal the nature of the pairing symmetry in KFe2As2 and pave the way for a unified theoretical description of unconventional superconductivity in iron-based materials.
- Norman Mannella
-
Article
| Open AccessDipolar skyrmions and antiskyrmions of arbitrary topological charge at room temperature
Control over magnetic skyrmions at room temperature has important applications in technology. Now the observation of skyrmions with high topological charge widens the potential for them to be used in unconventional computing techniques.
- Mariam Hassan
- , Sabri Koraltan
- & Manfred Albrecht
-
Article
| Open AccessEngineering multimode interactions in circuit quantum acoustodynamics
Quantum gates require controlled interactions between different degrees of freedom. A tunable coupling has now been demonstrated between the phonon modes of a mechanical resonator designed for storing and manipulating quantum information.
- Uwe von Lüpke
- , Ines C. Rodrigues
- & Yiwen Chu
-
Article |
Self-organized intracellular twisters
Cytoplasmic flows in the fruit fly oocyte can reorganize cellular components. These structured vortical flows arise through self-organizing dynamics of microtubules, molecular motors and cytoplasm.
- Sayantan Dutta
- , Reza Farhadifar
- & Michael J. Shelley
-
Article |
Hopping frustration-induced flat band and strange metallicity in a kagome metal
Electrons in f orbitals can create localized states that interact strongly and drive strange metal and critical behaviour via the Kondo mechanism. Now a mechanism of geometric frustration enables similar phenomena with d electrons.
- Linda Ye
- , Shiang Fang
- & Joseph G. Checkelsky
-
Research Briefing |
Defects show self-constraint in active nematics
Studies of a biological active nematic fluid reveal a spontaneous self-constraint that arises between self-motile topological defects and mesoscale coherent flow structures. The defects follow specific contours of the flow field, on which vorticity and strain rate balance, and hence, contrary to expectation, they break mirror symmetry.
-
Article |
Robust continuous time crystal in an electron–nuclear spin system
Time crystals spontaneously produce periodic oscillations that are robust to perturbations. A time crystal phase with a long coherence time has now been produced using the electron and nuclear spins of a semiconductor sample.
- A. Greilich
- , N. E. Kopteva
- & M. Bayer
-
Article |
Minimally rigid clusters in dense suspension flow
Dense suspensions are granular materials suspended in a liquid at high packing fractions, exhibiting high viscosity. The latter is now shown to be related to the formation of a network of rigid clusters at large shear stress.
- Michael van der Naald
- , Abhinendra Singh
- & Heinrich M. Jaeger
-
Article |
Origin of the critical state in sheared granular materials
When applying sufficient strain, the flow of dense granular matter becomes critical. It is now shown that this state corresponds to random loose packing for spheres with different friction coefficients and that these packings can be mapped onto the frictionless hard-sphere system.
- Yi Xing
- , Ye Yuan
- & Yujie Wang
-
Article |
Terahertz-field-driven magnon upconversion in an antiferromagnet
Inducing coherent interactions between distinct magnon modes—collective excitations of magnetic order—has been challenging. A canted antiferromagnet has demonstrated coherent magnon upconversion induced by terahertz laser pulses.
- Zhuquan Zhang
- , Frank Y. Gao
- & Keith A. Nelson
-
Article |
Nodal s± pairing symmetry in an iron-based superconductor with only hole pockets
High-precision photoemission measurements determine that the superconducting pairing symmetry in KFe2As2 is the same as in other types of iron-based superconductors, despite having different features in the band structure.
- Dingsong Wu
- , Junjie Jia
- & X. J. Zhou
-
Article |
Observation of possible excitonic charge density waves and metal–insulator transitions in atomically thin semimetals
The mechanism of charge density wave formation has been hard to explain due to accompanying structural distortions. Now low-dimensional HfTe2 is revealed to host a purely electronic exitonic charge density wave driven by reduced screening effects.
- Qiang Gao
- , Yang-hao Chan
- & Peng Chen
-
Article
| Open AccessFalse vacuum decay via bubble formation in ferromagnetic superfluids
The transition from a metastable state to the ground state in classical many-body systems is mediated by bubble nucleation. This transition has now been experimentally observed in a quantum setting using coupled atomic superfluids.
- A. Zenesini
- , A. Berti
- & G. Ferrari
-
Article |
Raman sideband cooling of molecules in an optical tweezer array
Raman sideband cooling is a method used to prepare atoms and ions in their vibrational ground state. This technique has now been extended to molecules trapped in optical tweezer arrays.
- Yukai Lu
- , Samuel J. Li
- & Lawrence W. Cheuk
-
Article |
Rich proton dynamics and phase behaviours of nanoconfined ices
The phase diagram of confined ice is different from that of bulk ice. Simulations now reveal several 2D ice phases and show how strong nuclear quantum effects result in rich proton dynamics in 2D confined ices.
- Jian Jiang
- , Yurui Gao
- & Xiao Cheng Zeng
-
News & Views |
A kicked quasicrystal
Quasicrystals are ordered but not periodic, which makes them fascinating objects at the interface between order and disorder. Experiments with ultracold atoms zoom in on this interface by driving a quasicrystal and exploring its fractal properties.
- Julian Léonard
-
Article |
Covariant quantum kernels for data with group structure
The kernel method in machine learning can be implemented on near-term quantum computers. A 27-qubit device has now been used to solve learning problems using kernels that have the potential to be practically useful.
- Jennifer R. Glick
- , Tanvi P. Gujarati
- & Kristan Temme
-
Article |
Quasi-crystalline order in vibrating granular matter
In quasi-crystals, constituents do not form spatially periodic patterns, but their structures still give rise to sharp diffraction patterns. Now, quasi-crystalline patterns are found in a system of spherical macroscopic grains vibrating on a substrate.
- A. Plati
- , R. Maire
- & G. Foffi
-
Article |
Universality class of a spinor Bose–Einstein condensate far from equilibrium
The dynamics of isolated quantum many-body systems far from equilibrium is the object of intense research. Magnetization measurements in a spinor atomic gas now offer a way to classify universal dynamics based on symmetry and topology.
- SeungJung Huh
- , Koushik Mukherjee
- & Jae-yoon Choi
-
Article
| Open AccessInverse design of high-dimensional quantum optical circuits in a complex medium
Light passing through complex media is subject to scattering processes that mix together different photonic modes. This complexity can be harnessed to implement quantum operations.
- Suraj Goel
- , Saroch Leedumrongwatthanakun
- & Mehul Malik
-
Article
| Open AccessSpontaneous self-constraint in active nematic flows
Active flows in biological systems swirl. A coupling between active flows, elongated deformations and defect dynamics helps preserve self-organised structures against disordered swirling.
- Louise C. Head
- , Claire Doré
- & Tyler N. Shendruk
-
Article
| Open AccessNon-Hermitian topology in a multi-terminal quantum Hall device
Non-Hermitian systems can be described in terms of gain and loss with a coupled environment—a hard feature to tune in quantum devices. Now an experiment shows non-Hermitian topology in a quantum Hall ring without relying on gain and loss.
- Kyrylo Ochkan
- , Raghav Chaturvedi
- & Ion Cosma Fulga
-
Article
| Open AccessEmergent seesaw oscillations during cellular directional decision-making
Cell motion along linear confinements is deterministic. Now a model predicts deterministic oscillations in cellular polarization at a Y junction in a set-up with adhesive patterns.
- Jonathan E. Ron
- , Michele Crestani
- & Nir S. Gov
-
Article
| Open AccessSecond-scale rotational coherence and dipolar interactions in a gas of ultracold polar molecules
Coherence between rotational states of polar molecules has previously been limited by light shifts in optical traps. A magic-wavelength trap is able to maximize the coherence time and enables the observation of tunable dipolar interactions.
- Philip D. Gregory
- , Luke M. Fernley
- & Simon L. Cornish
-
Article
| Open AccessAnomalous localization in a kicked quasicrystal
Phases of matter can host different transport behaviours, ranging from diffusion to localization. Anomalous transport has now been observed in an interacting Bose gas in a one-dimensional lattice subject to a pulsed incommensurate potential.
- Toshihiko Shimasaki
- , Max Prichard
- & David M. Weld
-
Article
| Open AccessFlexoelectric polarizing and control of a ferromagnetic metal
Electric polarization is well defined for insulators but not for metals. Electric-like polarization is now realized via inhomogeneous lattice strain in metallic SrRuO3, generating a pseudo-electric field. This field affects the material’s electronic bands.
- Wei Peng
- , Se Young Park
- & Daesu Lee
-
Article
| Open AccessLong-lived valley states in bilayer graphene quantum dots
Using the valley degree of freedom in analogy to spin to encode qubits could be advantageous as many of the known decoherence mechanisms do not apply. Now long relaxation times are demonstrated for valley qubits in bilayer graphene quantum dots.
- Rebekka Garreis
- , Chuyao Tong
- & Wei Wister Huang
-
Article |
Heavy-tailed neuronal connectivity arises from Hebbian self-organization
The strengths of connections in networks of neurons are heavy-tailed, with some neurons connected much more strongly than most. Now a simple network model can explain how this heavy-tailed connectivity emerges across four different species.
- Christopher W. Lynn
- , Caroline M. Holmes
- & Stephanie E. Palmer
-
Article |
Diversity of information pathways drives sparsity in real-world networks
Topological features such as modularity and small-worldness are common in real-world networks. The emergence of such features may be driven by a trade-off between information exchange and response diversity that resembles thermodynamic efficiency.
- Arsham Ghavasieh
- & Manlio De Domenico
-
Editorial |
Twenty years of 2D materials
Two-dimensional crystals have revolutionized fundamental research across a staggering range of disciplines. We take stock of the progress gained after twenty years of work.
-
News & Views |
A new way to use old codes
Scalable quantum computers require quantum error-correcting codes that can robustly store information. Exploiting the structure of well-known classical codes may help create more efficient approaches to quantum error correction.
- Anirudh Krishna
-
Measure for Measure |
Squeeze it tight
Quantum technologies change our notion of measurement. Chenyu Wang elaborates on how quantum squeezing enhances the precision of gravitational-wave interferometers.
- Chenyu Wang
-
-
Article
| Open AccessProgrammable Heisenberg interactions between Floquet qubits
External driving of qubits can exploit their nonlinearity to generate different forms of interqubit interactions, broadening the capabilities of the platform.
- Long B. Nguyen
- , Yosep Kim
- & Irfan Siddiqi
-
Article |
Ferroelectric and spontaneous quantum Hall states in intrinsic rhombohedral trilayer graphene
Bilayer graphene is known to host states where interactions dominate the electronic behaviour. Now, transport measurements show that this is also true for trilayer graphene and give evidence for ferroelectric states and states with high Chern number.
- Felix Winterer
- , Fabian R. Geisenhof
- & R. Thomas Weitz
-
Article
| Open AccessTime-Efficient Constant-Space-Overhead Fault-Tolerant Quantum Computation
Large quantum computers will require error correcting codes, but most proposals have prohibitive requirements for overheads in the number of qubits, processing time or both. A way to combine smaller codes now gives a much more efficient protocol.
- Hayata Yamasaki
- & Masato Koashi
-
News & Views |
Parallel quantum control meets optical atomic clocks
Optical atomic clocks are extremely accurate sensors despite the poor use of their resources. A parallel quantum control approach might help to optimize the resources of optical atomic clocks, which could lead to an exponential improvement in their performance.
- Simone Colombo
-
Article |
Probing many-body correlations using quantum-cascade correlation spectroscopy
Quantum-correlated photons typically characterize strongly nonlinear quantum emitters. A two-photon correlation spectroscopy method now provides a powerful probe of weakly nonlinear many-body quantum systems.
- Lorenzo Scarpelli
- , Cyril Elouard
- & Thomas Volz
-
Article |
Emergence of highly coherent two-level systems in a noisy and dense quantum network
Quantum coherence is hard to maintain in solid-state systems, as interactions usually lead to fast dephasing. Exploiting disorder effects and interactions, highly coherent two-level systems have now been realized in a rare-earth insulator compound.
- A. Beckert
- , M. Grimm
- & G. Aeppli