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Using quantum gas microscopy, Hilbert space fragmentation and fractonic excitations are observed in a two-dimensional tilted Bose–Hubbard model.

Qudits, higher-dimensional analogues of qubits, expand quantum state space for information processing using fewer physical units. Here the authors demonstrate control over a 16-dimensional Hilbert space, equivalent to four qubits, using combined electron-nuclear states of a single Sb donor atom in Si.

For some states in quantum gravity, notions of locality can deviate from effective field theory predictions. Here, the authors show that such deviations can be recast in the quantum information framework of “overlapping qubits”.

Qutrits, or quantum three-level systems, can provide advantages over qubits in certain quantum information applications, and high-fidelity single-qutrit gates have been demonstrated. Goss et al. realize high-fidelity entangling gates between two superconducting qutrits that are universal for ternary computation.

This study provides direct neurophysiological evidence from over 30 human subjects showing that the anterior and posterior hippocampus are functionally distinct, with differences in theta activity linked to recollection and novelty processing.

Wu, Zhang and colleagues introduce ‘compare and contrast spatial transcriptomics’ (CoCo-ST), a graph contrastive learning-based method for spatial transcriptomics analysis that detects low-variance structures.

Standard ways of characterising quantum states incur exponential overhead. Here, the authors consider the task of reconstructing density matrices of multimode continuous variable systems, and demonstrate a method which scales polynomially with the system size, provided the state lies in a polynomial dimensional subspace.

Aberrant synchronous oscillations have been associated with numerous brain disorders, including essential tremor. The authors show that synchronous cerebellar activity can casually affect essential tremor and that its underlying mechanism may be related to the temporal coherence of the tremulous movement.

A Bell-like experiment that discriminates between real-number and complex-number multipartite quantum systems could disprove real quantum theory.

Quantum computing is a promising technology to solve complex challenges that would take classical computers an impractical amount of time. This Perspective discusses the current state of quantum computing and possible applications in enzyme engineering and biocatalysis.

A large nuclear spin has been successfully placed in a Schrödinger cat state, a superposition of its two most widely separated spin coherent states. This can be used as an error-correctable qubit.

The spectral gap problem—whether the Hamiltonian of a quantum many-body problem is gapped or gapless—is rigorously proved to be undecidable; there exists no algorithm to determine whether an arbitrary quantum many-body model is gapped or gapless, and there exist models for which the presence or absence of a spectral gap is independent of the axioms of mathematics.

Using voltage imaging, the authors show that interneurons in the hippocampus sharpen memory-encoding-activity by increasing the signal-to-noise ratio of pyramidal neuron sensory representations during working memory in mice.

Complex-valued neural networks can recognize phase-sensitive data in wave-related phenomena. Here, authors report a complex-valued optical convolution accelerator operating at over 2 TOPS for recognition of radar images, represents advances towards real-time analysis of complex satellite data.

Scattering resonances are quantum effects occurring in low-temperature molecular collisions. Here the authors observe resonances for the six-atom ND₃-H₂/HD systems in velocity map imaging experiments explained by high-level theoretical predictions.

The single-cell gene expression changes during spinal cord formation and neurogenesis in mice are unclear. Here, the authors use a HES5 reporter to live image, then mathematically model, oscillations in single cells in presumed progenitors and neurons of the developing spinal cord.

Integral equations are used in science and engineering to model complex systems with non-local dependencies; however, existing traditional and machine-learning-based methods cannot yield accurate or efficient solutions in several complex cases. Zappala and colleagues introduce a neural-network-based method that can learn an integral operator and its dynamics from data, demonstrating higher accuracy or scalability compared with several state-of-the-art methods.

Bosonic qubits can be engineered to feature intrinsic protection against certain kinds of errors, which makes quantum error correction across many bosonic qubits possible with less overhead.

Quantum spin-ice phases are predicted to have emergent gauge fields and fractionalization. Neutron scattering and thermodynamic measurements of the quantum spin-ice candidate Ce₂Zr₂O₇ show features consistent with these predictions.

Quantum state tomography is the process of retrieving the values that define a quantum system, but realizing it experimentally can be burdensome. Here, the authors provide an alternative approach via the expectation values of a set of non-Hermitian matrices, and characterize a 100,000-dimensional state.

Understanding past warming events is essential to project the consequences of anthropogenic carbon emissions. Here, carbon and hydrological cycle changes of the Carnian Pluvial Episode are revealed, offering insights into Earth System functioning.

Gaggioli, Lo et al. show that the histone methyltransferase EHMT2/G9a catalyses heterochromatin assembly at stressed replication forks. Untimely heterochromatin disassembly by demethylase KDM3A exposes forks to PRIMPOL-mediated genome instability.

The use of time-bin entangled qudits is hindered by the phase instability, timing inaccuracy and low scalability of current interferometric schemes. Here, the authors show a fiber-pigtailed photonic chip for generating and processing picosecond-spaced time-bin entangled qudits and utilize the system to implement a quantum key distribution protocol.

Coherent noise affecting a random error correcting code is now shown to produce a transition between phases that accumulate and destroy magic.

Multimodal results (iEEG, fMRI and MEG) of predictions from integrated information theory and global neuronal workspace theory align with some predictions of both theories on visual consciousness, but also critically challenge key tenets of both theories.

Quantum supremacy is demonstrated using a programmable superconducting processor known as Sycamore, taking approximately 200 seconds to sample one instance of a quantum circuit a million times, which would take a state-of-the-art supercomputer around ten thousand years to compute.

Timing is key for efficient coding and communication across brain areas. Here, the authors found that the medial septum orchestrates hippocampal network activity at multiple temporal scales likely mediating memory encoding and retrieval.

A violation of Bell's inequality, which is a direct proof of entanglement, can be observed in the solid state using the electron and nuclear spins of a single phosphorus atom in silicon.

Understanding surface carrier dynamics enables the design of optimal optoelectronic devices. Yang et al. find that surface recombination limits the total carrier lifetime in polycrystalline lead iodide perovskite films, meaning recombination at surfaces is more important than within and between grains.

Critical slowing (associated with increased variance and autocorrelation) can precede critical state transitions. Here, the authors show critical slowing can be used as a marker in seizure forecasting algorithms.

Superconducting quantum processors need to balance intentional disorder (to protect qubits) and nonlinear resonator coupling (to manipulate qubits), while avoiding chaotic instabilities. Berke et al. use the techniques of many-body localization theory to study the stability of current platforms against quantum chaos.

Waves are ubiquitous in nature and occur across various scales and settings. In this Primer, Jafarzadeh et al. discuss techniques for preprocessing and analysing waves, including information on choosing the appropriate methods based on wave properties, and present worked examples using synthetic datasets.

The magnetocaloric effect is well understood in spin-frustrated low-dimensional systems, and should be observable in certain high-symmetry molecular structures. Here, the authors report the experimental observation of sub-Kelvin cooling with a molecular magnet, and probe the low-temperature spin behaviour.

Superconductivity reported in metals driven away from equilibrium via optical pumping has been proposed to arise from nonlinear coupling between electrons and optically excited phonons. The authors use an exact approach to show that here, disorder, which disfavors superconductivity, emerges even though the system is translationally invariant.

Despite being a paradigmatic description of dissipative quantum dynamics, implementations of spin-boson models with trapped ions had limited tunability. Here, the authors demonstrate a trapped-ion quantum simulator of spin-boson dynamics with controllable bath spectral density, contributing towards scalable simulations of energy transfer processes.

A method to engineer higher-order interactions between photons provides a route to create non-classical and entangled states across multiple modes.

The segmentation motor activity of the small intestine is believed to be a result of alternating inhibitory and excitatory neural activity. Huizinga et al.show that the segmentation motor pattern is in fact a result of phase–amplitude interactions of slow-wave activities generated by two networks of interstitial cells of Cajal.

It is generally believed that most eigenstates of quantum chaotic models are ergodic. In this work, the authors disprove this by showing that all eigenstates of the Dicke model in the chaotic regime are scarred, and that ergodicity is an ensemble property, achievable only in the temporal average.

The whisking oscillator—consisting of parvalbumin-expressing inhibitory neurons located in the vibrissa intermediate reticular nucleus—in mice is an all-inhibitory network and recurrent synaptic inhibition has a key role in its rhythmogenesis.

The biological mechanisms of rehabilitation after stroke are not fully understood. Here authors identify parvalbumin interneurons as a key mediator of rehabilitation-induced stroke recovery and a drug targeting these neurons as a potential therapy.

Humans have a capacity for hierarchical cognitive control—the ability to simultaneously control immediate actions while holding more abstract goals in mind. The authors show that neural oscillations establish dynamic communication networks within the frontal cortex and that these oscillations coordinate local neural activity with increasing cognitive control.

Seismic reflection imaging beneath the northeastern Yellowstone caldera reveals a sharp boundary at about 3.8 km depth, which is inferred to result from a mixture of supercritical fluid and magma filling the pore space.

An error detecting code running on a trapped-ion quantum computer protects expressive circuits of eight logical qubits with a high-fidelity and partially fault-tolerant implementation of a universal gate set.

Superconducting giant atoms are realized in a waveguide by coupling small atoms to the waveguide at multiple discrete locations, producing tunable atom–waveguide coupling and enabling decoherence-free interactions.

In addition to light intensity, changes in pupil diameter are correlated with mental effort, attention and levels of arousal. Reimer et al. report that across behavioural states, fluctuations in pupil diameter are highly correlated with activity of noradrenergic and cholinergic projection neurons.

Brain slices offer an experimental window into human neurophysiology. Using high-density microelectrode array recordings and adeno-associated virus–mediated optogenetics, the authors demonstrate that optogenetic targeting of CAMK2A+ neurons can affect network activity in human hippocampal slices.

Signal processing is key to communications and video image processing for astronomy, medical diagnosis, autonomous driving, big data and AI. Menxi Tan and colleagues report a photonic processor operating at 17Tb/s for ultrafast robotic vision and machine learning.

Motor patterns underlying the rodent exploratory behaviours whisking and sniffing are coordinated by respiratory centres in the ventral medulla; a distinct region in the ventral medulla provides rhythmic input to the facial motor neurons that drive scanning by the vibrissae, and input from the pre-Bötzinger complex coordinates whisking with sniffing and basal breathing.

Autonomous quantum error correction protects quantum systems against decoherence through engineered dissipation. Here the authors introduce the Star code, which actively corrects single-photon loss and passively suppresses low-frequency dephasing and implement it in a two-transmon device.