Charge density waves are the periodic spatial modulation of electrons in a solid. A new experiment reveals that they can originate from two different electronic bands in a prototypical transition metal dichalcogenide, NbSe2.

To test the validity of theoretical models, the predictions they make must be compared with experimental data. Instead of choosing one model out of many to describe mass measurements of zirconium, Bayesian statistics allows the averaging of a variety of models.

Organisms acquire and use information from their environment to guide their behaviour. However, it is unclear whether this information quantitatively limits their performance at behavioural tasks. Here we relate information to the ability of Escherichia coli to navigate up chemical gradients, the behaviour known as chemotaxis. First, we derive a theoretical limit on the speed with which cells climb

Protons and neutrons in the atomic nucleus move in shells analogous to the electronic shell structures of atoms. The nuclear shell structure varies as a result of changes in the nuclear mean field with the number of neutrons N and protons Z, and these variations can be probed by measuring the mass differences between nuclei. The N = Z = 40 self-conjugate nucleus 80Zr is of particular interest, as its

Lanthanide atoms have an unusual electron configuration, with a partially filled shell of f orbitals. This leads to a set of characteristic properties, including large numbers of optical transitions with widely varying wavelengths and transition strengths, anisotropic interaction properties between atoms and with light, and a large magnetic moment and spin space present in the ground state, that enable

A particular strength of ultracold quantum gases is the range of versatile detection methods that are available. As they are based on atom–light interactions, the whole quantum optics toolbox can be used to tailor the detection process to the specific scientific question to be explored in the experiment. Common methods include time-of-flight measurements to access the momentum distribution of the gas

Ultralight axion-like particles are well-motivated dark matter candidates introduced by theories beyond the standard model of particle physics. However, directly constraining their parameter space with laboratory experiments usually yields weaker limits than indirect approaches relying on astrophysical observations. Here we report the search for axion-like particles with a quantum sensor in the mass

The early development of many organisms involves the folding of cell monolayers, but this behaviour is difficult to reproduce in vitro; therefore, both mechanistic causes and effects of local curvature remain unclear. Here we study epithelial cell monolayers on corrugated hydrogels engineered into wavy patterns, examining how concave and convex curvatures affect cellular and nuclear shape. We find

Laser cooling exploits the physics of light scattering to cool atomic and molecular gases to close to absolute zero. It is the crucial initial step for essentially all atomic gas experiments in which Bose–Einstein condensation and, more generally, quantum degeneracy is reached. The ongoing development of laser-cooling methods has allowed more elements to be brought to quantum degeneracy, with each

Single atoms and molecules can be trapped in tightly focused beams of light that form ‘optical tweezers’, affording exquisite capabilities for the control and detection of individual particles. This approach has progressed to creating tweezer arrays holding hundreds of atoms, resulting in a platform for controlling large many-particle quantum systems. Here we review this new approach to microscopic

Active matter can have macroscopic properties that defy the usual laws of hydrodynamics. Now these tell-tale properties have been traced down to the non-equilibrium character and handedness of interactions between individual particles.

The 2021 Nobel Prize in Physics has been awarded to Syukuro Manabe, Klaus Hasselmann and Giorgio Parisi “for groundbreaking contributions to our understanding of complex physical systems”.

The laws governing electrolysis developed by Michael Faraday, who originally trained as a bookbinder, led to the determination of the Faraday constant, as Daren Caruana recounts.

Precise measurements of the annihilation of an electron–positron pair into a neutron–antineutron pair allow us to take a look inside the neutron to better understand its complex structure.

Active materials are characterized by continuous injection of energy at the microscopic level and typically cannot be adequately described by equilibrium thermodynamics. Here we study a class of active fluids in which equilibrium-like properties emerge when fluctuating and activated degrees of freedom are statistically decoupled, such that their mutual information is negligible. We analyse three paradigmatic

The complicated structure of the neutron cannot be calculated using first-principles calculations due to the large colour charge of quarks and the self-interaction of gluons. Its simplest structure observables are the electromagnetic form factors1, which probe our understanding of the strong interaction. Until now, a small amount of data has been available for the determination of the neutron structure

Interacting quantum systems are difficult to formulate theoretically, but Nikolai Bogoliubov offered a workaround more than 70 years ago that has stood the test of time. Now, correlations that are a crucial feature of his theory have been observed.

Flat electronic bands, characteristic of ‘magic-angle’ twisted bilayer graphene, host many correlated phenomena1,2,3,4,5,6,7,8,9. Nevertheless, many properties of these bands and emerging symmetry-broken phases are still poorly understood. Here we use scanning tunnelling spectroscopy to examine the evolution of the twisted bilayer graphene bands and related gapped phases as the twist angle between

Quantum fluctuations play a central role in the properties of quantum matter. In non-interacting ensembles, they manifest as fluctuations of non-commuting observables, quantified by Heisenberg inequalities1. In the presence of interactions, additional quantum fluctuations appear, from which many-body correlations and entanglement arise2. Weak interactions are predicted to deplete Bose–Einstein condensates

Clonal dominance arises when the descendants (clones) of one or a few founder cells contribute disproportionally to the final structure during collective growth1,2,3,4,5,6,7,8. In contexts such as bacterial growth, tumorigenesis and stem cell reprogramming2,3,4, this phenomenon is often attributed to pre-existing propensities for dominance, whereas in stem cell homeostasis, neutral drift dynamics are

Having long played the role of collaborators with other, more renowned, institutions, historically disadvantaged South African universities are now challenging the status quo — and emerging as leaders.

It has long been assumed that the quantum statistics of light are preserved when photons interact with plasmons. An analysis of the scattering process shows that this is not always the case, as light can mix and match different plasmonic pathways.

Most systems exhibiting topological superconductivity are artificial structures that require precise engineering. Now, a layered material shows tantalizing signs of the phenomenon.

Topological superconductors are an essential component for topologically protected quantum computation and information processing. Although signatures of topological superconductivity have been reported in heterostructures, material realizations of intrinsic topological superconductors are rather rare. Here we use scanning tunnelling spectroscopy to study the transition metal dichalcogenide 4Hb-TaS2

Recent successes in producing intermediate-scale quantum devices have focused interest on establishing whether near-term devices could outperform classical computers for practical applications. A central question is whether noise can be overcome in the absence of quantum error correction or if it fundamentally restricts any potential quantum advantage. We present a transparent way of comparing classical

The life and death of an organism rely on correct cell division, which occurs through the process of mitosis. Although the biochemical signalling and morphogenetic processes during mitosis are well understood, the importance of mechanical forces and material properties is only just starting to be discovered. Recent studies have revealed that the layer of proteins beneath the cell membrane—the so-called

A rich variety of physical effects in spin dynamics arise at the interface between different magnetic materials1. Engineered systems with interlaced magnetic structures have been used to implement spin transistors, memories and other spintronic devices2,3. However, experiments in solid-state systems can be difficult to interpret because of disorder and losses. Here we realize analogues of magnetic

The most well-known example of an ordered quantum state—superconductivity—is caused by the formation and condensation of pairs of electrons. Fundamentally, what distinguishes a superconducting state from a normal state is a spontaneously broken symmetry corresponding to the long-range coherence of pairs of electrons, leading to zero resistivity and diamagnetism. Here we report a set of experimental

Molecular spin qubits that can be controlled electrically are typically susceptible to decoherence. Holmium molecular spins provide a solution by combining robust coherence with strong spin–electric coupling.

At high pressure and temperature, water forms two crystalline phases, known as hot ‘black’ ices due to their partial opaqueness. A detailed characterization of these phases may explain magnetic field formation in giant icy planets like Neptune.

Integrating quantum technology with existing telecom infrastructure is hampered by a mismatch in operating frequencies. An optomechanical resonator now offers a strain-mediated spin–photon interface for long-distance quantum networks.

Electrical control of spins at the nanoscale offers significant architectural advantages in spintronics, because electric fields can be confined over shorter length scales than magnetic fields1,2,3,4,5. Thus, recent demonstrations of electric-field sensitivities in molecular spin materials6,7,8 are tantalizing, raising the viability of the quantum analogues of macroscopic magneto-electric devices9

A coherent ensemble of spins interfaced with a proxy qubit is an attractive platform to create many-body coherences and probe the regime of collective excitations. An electron spin qubit in a semiconductor quantum dot can act as such an interface to the dense nuclear spin ensemble within the quantum dot consisting of multiple high-spin atomic species. Earlier work has shown that the electron can relay

In the phase diagram of water, superionic ices with highly mobile protons within the stable oxygen sublattice have been predicted at high pressures. However, the existence of superionic ices and the location of the melting line have been challenging to determine from both theory and experiments, yielding contradictory results depending on the employed techniques and the interpretation of the data.

Quantum networks enable a broad range of practical and fundamental applications spanning from distributed quantum computing to sensing and metrology. A cornerstone of such networks is an interface between telecom photons and quantum memories, which has proven challenging for the case of spin-mechanical memories. Here we demonstrate a novel approach based on cavity optomechanics that utilizes the susceptibility

A microscopy technique allows the identification of parameters in a paradigmatic model of condensed-matter physics.

The measurement of pH is more complicated than it seems, recalls Andrea Taroni.

Publicly funded nuclear fusion laboratories are experiencing competition from the private sector, giving new energy to the field.

In a study on high-harmonic generation from a dense atomic xenon gas, the strong-field light–matter interaction is shown to leave a quantum mechanical imprint on the incident light that escapes the semiclassical picture of strong-field physics.

The crystal structure of a solid largely dictates its electronic, optical and mechanical properties. Indeed, much of the exploration of quantum materials in recent years including the discovery of new phases and phenomena in correlated, topological and two-dimensional materials—has been based on the ability to rationally control crystal structures through materials synthesis, strain engineering or

Singularities are common in diverse physical systems1 and lead to universal structures2,3. This universality suggests that they should also naturally arise in biological systems, where active growth, autonomous motion, kinesis and taxis focus deformations in spacetime, as exemplified in the morphogenetic processes determining biological size and shape4. A familiar example of a morphogenetic singularity

Complex networks have become the main paradigm for modelling the dynamics of interacting systems. However, networks are intrinsically limited to describing pairwise interactions, whereas real-world systems are often characterized by higher-order interactions involving groups of three or more units. Higher-order structures, such as hypergraphs and simplicial complexes, are therefore a better tool to

Organ development involves complex shape transformations driven by active mechanical stresses that sculpt the growing tissue1,2. Epithelial gland morphogenesis is a prominent example where cylindrical branches transform into spherical alveoli during growth3,4,5. Here we show that this shape transformation is induced by a local change from anisotropic to isotropic tension within the epithelial cell

The interplay between strong electron–electron interactions and band topology can produce electronic states that spontaneously break symmetries. The discovery of flat bands in magic-angle twisted bilayer graphene (MATBG)1,2,3 with non-trivial topology4,5,6,7 has provided a compelling platform in which to search for new symmetry-broken phases. Recent scanning tunnelling microscopy8,9 and transport experiments10

General-purpose quantum computers can, in principle, entangle a number of noisy physical qubits to realize composite qubits protected against errors. Architectures for measurement-based quantum computing intrinsically support error-protected qubits and are the most viable approach for constructing an all-photonic quantum computer. Here we propose and demonstrate an integrated silicon photonic scheme

The single-particle and many-body properties of twisted bilayer graphene (TBG) can be dramatically different from those of a single graphene layer, particularly when the two layers are rotated relative to each other by a small angle (θ ≈ 1°), owing to the moiré potential induced by the twist. Here we probe the collective excitations of TBG with a spatial resolution of 20 nm, by applying mid-infrared

The tin isotope 100Sn is key to understanding nuclear stability, but little is known about its properties. Precision measurements of closely related indium isotopes have now pinned down its mass.

Most water in the Universe may be superionic, and its thermodynamic and transport properties are crucial for planetary science but difficult to probe experimentally or theoretically. We use machine learning and free-energy methods to overcome the limitations of quantum mechanical simulations and characterize hydrogen diffusion, superionic transitions and phase behaviours of water at extreme conditions

The tin isotope 100Sn is of singular interest for nuclear structure due to its closed-shell proton and neutron configurations. It is also the heaviest nucleus comprising protons and neutrons in equal numbers—a feature that enhances the contribution of the short-range proton–neutron pairing interaction and strongly influences its decay via the weak interaction. Decay studies in the region of 100Sn have

Topological phases of matter connect mathematical principles to real materials, and may shape future electronic and quantum technologies. So far, this discipline has mostly focused on single-gap topology described by topological invariants such as Chern numbers. Here, based on a tunable kagome model, we observe non-Abelian band topology and its transitions in acoustic semimetals, in which the multi-gap

In the presence of interactions, electrons in condensed-matter systems can behave hydrodynamically, exhibiting phenomena associated with classical fluids, such as vortices and Poiseuille flow1,2,3. In most conductors, electron–electron interactions are minimized by screening effects, hindering the search for hydrodynamic materials; however, recently, a class of semimetals has been reported to exhibit

Quantum states with long-lived coherence are essential for quantum computation, simulation and metrology. The nuclear spin states of ultracold molecules prepared in the singlet rovibrational ground state are an excellent candidate for encoding and storing quantum information. However, it is important to understand all sources of decoherence for these qubits, and then eliminate them, to reach the longest

This month, we celebrate the discovery of electromagnetic rotation, the principle behind the electric motor.

The European Researchers’ Night provides a platform for scientists to engage with the public.

The uptake of graphene-based materials calls for standardization. Silvia Milana explains what this entails.

Ultracold polar molecules possess long-range, anisotropic and tunable dipolar interactions, providing opportunities to probe quantum phenomena that are inaccessible with existing cold gas platforms. However, experimental progress has been hindered by the dominance of two-body loss over elastic interactions, which prevents efficient evaporative cooling. Although recent work has demonstrated controlled

Scanning tunnelling microscopy reveals an unexpected periodicity in the local density of states of a transition metal dichalcogenide — with a puzzling wavelength that casts the material as a quantum spin liquid.

Two-dimensional triangular-lattice antiferromagnets are predicted under some conditions to exhibit a quantum spin liquid ground state with no energy barrier to create emergent, fractionalized spinon excitations that carry spin but no charge. Materials that realize this kind of spin liquid are expected to have a low-energy behaviour described by a spinon Fermi surface. Directly imaging the resulting

The physics of intense laser–matter interactions1,2 is described by treating the light pulses classically, anticipating no need to access optical measurements beyond the classical limit. However, the quantum nature of the electromagnetic fields is always present3. Here we demonstrate that intense laser–atom interactions may lead to the generation of highly non-classical light states. This was achieved

Charged particles can be accelerated to high energies by collisionless shock waves in astrophysical environments, such as supernova remnants. By interacting with the magnetized ambient medium, these shocks can transfer energy to particles. Despite increasing efforts in the characterization of these shocks from satellite measurements at Earth’s bow shock as well as powerful numerical simulations, the