Quantum information is typically fragile under measurements and environmental coupling. Remarkably, we find that its lifetime can scale exponentially with system size when the environment is continuously monitored via midcircuit measurements—regardless of bath size. Starting from a maximally entangled state with a reference, we analytically prove this exponential scaling for typical Haar-random unitaries and confirm it through numerical simulations in both random unitary circuits and chaotic Hamiltonian systems. In the absence of bath monitoring, the lifetime exhibits a markedly different scaling: It grows at most linearly—or remains constant—with system size and decays inversely with the bath size. We further extend our findings numerically to a broad class of initial states. In the intermediate regime of partial monitoring, we identify and prove a two-scale transition, where the quantum mutual information decays logarithmically at microscopic timescales but linearly at macroscopic timescales. We discuss implications for monitored quantum circuits in the weak-measurement limit, quantum algorithms such as quantum diffusion models and quantum reservoir computing, and quantum communication. Finally, we experimentally verify the gap of persisted information on IBM Quantum hardware.

Hydroplastification offers an eco-friendly route to plasticize hydrophilic polymers by enhancing chain mobility, yet it remains ineffective for rigid crystalline nanomaterials. Here, we report a novel plasticity mechanism governed by mesopores acting as structural free volume between rigid hydrophilic nanocrystals, cellulose nanocrystals (CNCs). During the mechanosorptive vapor training process to change the mesopores, the plasticity arises from a dynamic competition between external tensile stress and internal capillary forces. We establish a semiquantitative constitutive relationship revealing that the network’s wet-state yield strength is critically regulated by the aspect ratio and surface chemistry of the nanocrystals. Specifically, the weak acidity of carboxyl groups ($pKa\sim 3.2$) combined with high aspect ratios creates a defect-dominated soft skeleton; here, the internal Laplace pressure ($\sim 26\mathrm{MPa}$) exceeds the yield strength, driving the splitting of bottlelike mesopores into smaller domains until a geometric locking limit defined by the nanocrystal diameter is reached. In contrast, strong electrostatic repulsion from sulfonates ($pKa\sim 1.0$) or spatial jamming in short nanorods results in rigid networks that resist this capillary-driven densification. This novel hydroplastification mechanism by capitalizing on mesopores with competing capillary force, opposing network stress, and external stress enables shaping CNC films into stable geometries, rather than lattice disruption. Moreover, such findings extend hydroplasticity concepts to rigid matter, establishing mesopore engineering as a physical pathway to regulate the plasticity of crystalline nanomaterials.

One of the roadblocks toward the implementation of a fault-tolerant superconducting quantum processor is impacts of ionizing radiation with the qubit substrate. Such impacts temporarily elevate the density of quasiparticles (QPs) across the device, leading to correlated qubit error bursts. The most damaging errors, $T_1$ errors, stem from QP tunneling across the qubit Josephson junctions (JJs). Recently, we demonstrated [M. McEwen, K. Miao, et al., Phys. Rev. Lett. 133, 240601 (2024)] that this type of error can be strongly suppressed by engineering the profile of superconducting gap at the JJs in a way that prevents QP tunneling. In this work, we identify a new type of impact-induced correlated error that persists in the presence of gap engineering. We observe that impacts shift the frequencies of the affected qubits, and thus lead to correlated phase errors. The frequency shifts are systematically negative, reach values up to 3 MHz, and last for $\sim 1\mathrm{ms}$. We provide evidence that the shifts originate from QP-qubit interactions in the JJ region. Further, we demonstrate that the shift-induced phase errors can be detrimental to the performance of quantum error correction protocols.

Superionic conductors (SICs) exhibit liquidlike ionic diffusivities while maintaining a periodic crystalline lattice, making them promising candidates for applications in fuel cells, solid-state electrolytes, and thermoelectric materials. The transient local structures of mobile ions and their cooperative interactions with the host lattice are of pivotal importance regarding both the ion and heat conduction in SICs. However, accurately capturing the structural evolution of mobile ions remains a significant challenge due to the inherent complexities involved. Here, we employed ultrafast electron diffraction (UED) with femtosecond-temporal and angstrom-spatial resolution to resolve the structural evolution of mobile ${\mathrm{Ag}}^{+}$ ions in ${\mathrm{AgCrSe}}_2$. Our experiments identify a critical process originating from localized ${\mathrm{Ag}}^{+}$ vibrations at the long-range-ordered lattice sites to a formation of short-range-correlated ${\mathrm{Ag}}^{+}$ trimer structures through a drastic contraction of the ${\mathrm{Ag}}^{+}─{\mathrm{Ag}}^{+}$ bond from approximately 3.68 to approximately 3.00 Å in 1.97 ps. Combining real-time time-dependent density-functional-theory and molecular dynamics simulation, we further reveal the crucial role of these contracted trimer structures in enabling fast ${\mathrm{Ag}}^{+}$ diffusion by opening up excess free volume and reducing local energy barriers. Such an intimate relation between fast diffusion and local lattice variations is not exclusive and can be extended beyond ${\mathrm{AgCrSe}}_2$ to materials such as ${\mathrm{Li}}_{10}X{\mathrm{P}}_2{\mathrm{S}}_{12}$ ($X=\mathrm{Si}$, Ge, Sn). The ability to track ion diffusion with UED also provides new avenues for exploring the atomistic mechanisms of fast ion diffusion in next-generation solid-state electrolytes, fuel cells, and ion transport membranes.

Cell extrusion is an essential mechanism for controlling cell density in epithelial tissues. Another essential element of epithelia is curvature, which is required to achieve complex shapes, like in the lung or intestine. Here, we introduce a three-dimensional bubbly vertex model to study the interplay between extrusion and curvature. We find a generic cellular bulging instability at topological defects, which is much stronger than for standard vertex models. Analyzing cell shapes in three-dimensional imaging data of spherical mouse colon organoids, we infer that pentagonal cells have an increased basal interfacial tension, suggesting that cells at topological defects react to the different force conditions. Using the bubbly vertex model, we show that such basal tensions stabilize against the predicted instability and result in better cell shape control than tissue-scale mechanisms such as lumen pressure and spontaneous curvature. Our theory suggests that epithelial curvature naturally leads to bulged and extrusionlike cell shapes because the interfacial curvature of individual cells at the defects strongly amplifies buckling effected by tissue-scale topological defects in elastic sheets. Our results highlight the complex interplay of forces across scales in three-dimensional tissue organization.

Relaxor ferroelectrics exhibit exceptional dielectric and electromechanical properties, yet their microscopic origins remain elusive due to the interplay of hierarchical polar structures and chemical complexity. While models based on polar nanoregions or nanodomains offer valuable phenomenological insights, they often lack the first-principles predictive capability necessary for quantitatively describing functional properties such as piezoelectric coefficients. Here, we use large-scale molecular dynamics simulations, enabled by a universal first-principles-based machine-learning interatomic potential, to investigate atomic-scale polar dynamics in canonical Pb-, Bi-, and Ba-based relaxors. Across all systems, we uncover a universal dipolar nematic state, characterized by long-range orientational order of local polarizations without local alignment, challenging conventional polar-cluster-based paradigms. We introduce a universal order parameter, derived from the skewness of the distributions of the local polarization autocorrelation functions, that captures the thermal evolution of both lead-based and lead-free systems within a single master curve. This nematic order, and its robust structural memory under electric field cycling, underpins key relaxor phenomena, including diffuse phase transition, frequency-dependent dielectric dispersion, and reversible giant piezoelectricity. Our findings establish a unified microscopic framework for relaxors and present a broadly applicable statistical approach to understanding complex disordered materials.

Ultrastable glasses prepared from the physical vapor deposition of organic molecules present a very low density of two-level states, the kind of glass defects that determine their peculiar low-temperature thermal properties. Numerical simulations suggest that quasilocalized harmonic vibrational modes emerge in the soft regions associated with two-level states. However, the connection between the low-frequency vibrational modes and the local structural instabilities of glasses remains unexplained. Here, we exploit a recently developed spectrograph for nuclear resonant analysis of inelastic x-ray scattering to probe the density of vibrational states of amorphous thin films of ultrastable and conventional glasses down to an exceptionally low frequency of approximately 70 GHz. We show that the glass stability does not affect the harmonic vibrational modes at the lowest frequencies, despite a reduction of almost an order of magnitude in the density of two-level states. At the same time, the vibrational modes at higher frequencies, around the boson peak maximum, are extremely sensitive to the glass stability. Although we cannot exclude the possible existence of quasilocalized modes in glasses, we show that their presence is not strictly necessary to describe the measured density of low-frequency vibrations. The experimental developments here presented pave the way to the solution to the long-standing debate on the low-frequency vibrations in glasses.

The thermodynamic limit is foundational to statistical mechanics, underlying our understanding of many-body phases. It assumes that, as the system size grows infinitely at fixed density of particles, unambiguous macroscopic phases emerge that are independent of the system’s boundary shape. We present explicit quantum spin and dimer Hamiltonians whose ground states violate this principle. Our construction relies on the previous mathematical work on classical dimers on the Aztec diamond and the square-octagon fortress, where geometry-dependent phase behaviors are observed in the infinite-size limit. We reverse engineer quantum spin Hamiltonians on the square and the square-octagon lattices whose ground states at the Rokhsar-Kivelson points are described by classical dimer coverings. On diamond-shaped domains, we find macroscopic boundary regions exhibiting distinct quantum phases from those on square-shaped domains. We study the nature of these phases by calculating the dimer-dimer and vison correlators and adapt Kasteleyn matrix based analytical and numerical methods for computing the vison correlator, which are significantly more efficient than standard Monte Carlo techniques. Our results show that the square-octagon lattice supports a single gapped short-range entangled phase, with exponentially decaying dimer correlators and a constant vison correlator. When the same model is considered on a diamond-shaped domain, two additional macroscopic regions emerge, with one near the corners and exhibiting staggered dimer order, and another exhibiting critical correlations.

A swimming microorganism stirs the surrounding fluid, creating a flow field that governs not only its locomotion and nutrient uptake, but also its interactions with other microorganisms and the environment. Despite its fundamental importance, capturing this flow field and unraveling its biological implications remains a challenge. Here, we report direct, time-resolved measurements of the three-dimensional (3D) flow field generated by a single, free-swimming microalga, Chlamydomonas reinhardtii, a model organism for microbial locomotion and flagellar dynamics. Supported by hydrodynamic modeling and simulations, our measurements resolve how established two-dimensional (2D) flow features such as in-plane vortices and the stagnation point emerge from and shape the full algal flow in 3D. Moreover, we reveal unexpected low-Reynolds-number flow phenomena including micron-sized vortex rings and periodically recurring translating vortices and uncover topological changes in the underlying flow structure associated with the puller-to-pusher transition of an alga. Biologically, access to the 3D flow field enables rigorous quantification of the alga’s energy expenditure, as well as its swimming and feeding efficiency, improving the precision of these physiological metrics. Taken together, our study demonstrates rich vortex dynamics in inertialess flows and shows their influence on microbial motility. The work also introduces an experimental method for mapping the fluid environment sculpted by beating flagella.

“Hidden” phases, generated using ultrafast laser pulses (few hundred femtoseconds), with distinct properties than at the thermodynamic equilibrium, are appealing for technologies, as they can be long-lived, with a lifetime of hours or weeks, and reversible with temperature sweeping or extra pulses. In this regard, ${\mathrm{La}}_{2/3}{\mathrm{Ca}}_{1/3}{\mathrm{MnO}}_3$ (LCMO) stands out due to its tunability through epitaxial strain, which can drive the bulk ferromagnetic metal into an antiferromagnetic insulator (AFI), and its susceptibility to photoinduced transitions. Indeed, AFI LCMO displays a long-lived photoinduced transition into a putative hidden phase whose exact nature and excitations are still largely unknown. Here, we combine ultrafast photoexcitation in the near infrared with in situ transport, x-ray absorption, and resonant inelastic x-ray scattering (RIXS) to investigate the excitations (polarons, phonons, and orbital) of the photoexcited phase of LCMO and contrast them with the thermodynamic phases achieved through strain and temperature. In the thermodynamic regime, we establish the correlation between polarons and transport placing them in the “strong coupling” regime of the Holstein model. Upon photoexcitation of LCMO-AFI, we uncover a long-lived phase characterized by the softening of the polaron excitations, the partial suppression of the Jahn-Teller distortion, and nearly unchanged phonons, showing the emergence of a photoexcited state absent in the equilibrium phase diagram. Finally, by varying temperature, epitaxial strain, and photoexcitation fluence, we construct a polaron phase diagram and identify the key spectroscopic signatures of each phase. Our laser-RIXS approach establishes a versatile platform for exploring photoinduced hidden phases in quantum materials in nonstroboscopic conditions.

One of the premier utilities of present-day noisy quantum computers is simulation of many-body quantum systems. We study how long in time is such a discrete-time simulation representative of a continuous time Hamiltonian evolution; namely, a finite time step introduces so-called Trotterization errors. We demonstrate that the truncated operator propagator (Ruelle-Pollicott resonances) is a powerful tool to that end, as well as to study prethermalization and discrete-time crystals, including finding those phenomena at large gate duration. We show that the effective energy is more stable than suggested by Trotter errors—a manifestation of prethermalization—while all other observables are not. Even the most stable observable though deteriorates in the thermodynamic limit. Different than in classical systems with the strongest chaos, where the faithfulness time (the shadowing time) can be infinite, in quantum many-body chaotic systems it is finite. A corollary of our results is also that, opposite of previous claims, there is no Trotterization transition in nonintegrable many-body quantum systems. We demonstrate our results on a one-dimensional (1D) kicked Ising model, as well as on a 1D kicked XX model and a 2D kicked Ising model. The truncated propagator is also used to calculate the energy diffusion constant in the tilted-field Ising model with high accuracy.

We use high-resolution chemical potential measurements to extract the entropy of monolayer and bilayer graphene in the quantum Hall regime via the Maxwell relation $[(d\mu )/(dT)]{|}_N=-[(dS)/(dN)]{|}_T$. Measuring the entropy from $T=300\mathrm{K}$ down to $T=200\mathrm{mK}$, we identify the sequential emergence of quantum Hall ferromagnetism, fractional quantum Hall states, and various charge orders by comparing the measured entropy in different temperature regimes with theoretical models. At the lowest temperature of $T\approx 200\mathrm{mK}$ we perform a detailed study of the entropy near even-denominator fractional quantum Hall states in bilayer graphene, and comment on the possible topological origin of the observed excess entropy.

Model order reduction encompasses mathematical techniques aimed at reducing the complexity of mathematical models in simulations while retaining the essential characteristics and behaviors of the original model. This is particularly useful in the context of large-scale dynamical systems, which can be computationally expensive to analyze and simulate. Here, we present a model order reduction technique to reduce the time complexity of open quantum systems, grounded in the principle of measurement-adapted coarse graining. This method, governed by a coarse-graining timescale $\tau$ and the spectral band center ${\omega }_0$ of the measurement channel, organizes corrections to the lowest-order model which aligns with the rotating-wave approximation Hamiltonian in certain limits and rigorously justifies the resulting effective quantum master equation (EQME). The focus on calculating to a high degree of accuracy what can only be resolved by the measurement introduces a principled regularization procedure to address singularities and generates low-stiffness models suitable for efficient long-time integration. The closed-form EQME parameters greatly enhance interpretability, while the predicted EQME structure provides a foundation for deriving stochastic master equations under continuous measurement and for constructing efficient gray-box models for system identification and control. As a demonstration, we derive the fourth-order EQME for a challenging problem related to the dynamics of a superconducting qubit under high-power dispersive readout in the presence of a continuum of dissipative waveguide modes. This derivation shows that the lowest-order terms align with previous results, while higher-order corrections suggest new phenomena.

The preparation of high-fidelity non-Clifford (magic) states is an essential subroutine for universal quantum computation but imposes substantial space-time overhead. Magic-state factories based on high-rate and -distance quantum low-density parity-check (LDPC) codes equipped with transversal non-Clifford gates can potentially reduce these overheads significantly, by circumventing the need for multiple rounds of distillation and by producing a large number of magic states in a single code block. As a step toward realizing efficient, fault-tolerant magic-state production, we introduce a class of finite block-length quantum LDPC codes which we name tricycle codes, generalizing the well-known bicycle codes to three homological dimensions. These codes can support constant-depth physical circuits that implement logical $CCZ$ gates between three code blocks. To construct these constant-depth $CCZ$ circuits, we develop analytical and numerical techniques that apply to a broad class of three-dimensional homological and balanced-product codes. We further show that tricycle codes enable single-shot state preparation and error correction, leading to a highly efficient magic-state generation protocol. Numerical simulations of specific codes confirm robust performance under circuit-level noise, demonstrating a high circuit-noise threshold of $>0.5\%$. With modest postselection, certain tricycle codes of block lengths of only approximately 50–100 qubits are shown to produce $|\overline{CCZ}⟩$ magic states with logical error rates ranging from $2\times {10}^{-8}$ to below $3\times {10}^{-11}$. Finally, we construct optimal depth syndrome extraction circuits for tricycle codes and present a protocol for implementing them efficiently on a reconfigurable neutral-atom platform.

Quantum thermodynamics addresses the dynamics of heat flow in quantum devices driven out of equilibrium. Although mesoscopic circuits at low temperatures provide a flexible platform to explore this dynamics, experimental studies are wanting, because thermal timescales in nanodevices are often too fast. Here, we engineer and investigate with noise thermometry a mesoscopic thermal circuit where heat flows between electron, phonon, and nuclear systems can occur on slower timescales. The central constituent of this device is a micrometer-scale metallic island electrically connected to large cold electron reservoirs through two to four ballistic quantum Hall channels, a component frequently used for exploring stationary thermal currents. We uncover a two-step thermalization process specific to the mesoscopic scale, involving a fast initial temperature step followed by a much slower rise extending over minutes. This observation is quantitatively accounted for by the balance between heat flows through electronic quantum channels, to cold phonons, and to the nuclear spins in the metallic island. The disclosed mesoscopic thermalization takes a step into the field of quantum thermodynamical phenomena, highlighting their distinctive nature on a central constituent of quantum circuits. The implications for the thermal engineering of nanodevices include the thermal characterization of exotic states at high magnetic field.

A remarkable feat of active matter physics is that systems as diverse as collections of self-propelled particles, nematics mixed with molecular motors, and interacting robots can all be described by symmetry-based continuum theories. These descriptions rely on reducing complex effects of individual motors to a few key active parameters, which increase with activity. Here we observe a striking anomaly in the continuum description of nonreciprocal active solids, a ubiquitous class of active materials. Using a combination of metamaterial experiments and coarse-graining theory we find that as microscopic activity increases, macroscale active response can vanish: more is less. In this highly active regime, nonaffine and localized modes prevail and destroy the large-scale signature of microscopic activity. These modes exist in any dilute periodic structure and emerge in random lattices below a percolation transition. Our results unveil a counterintuitive facet of active matter, offering new principles for engineering materials far from equilibrium.

In thermoelectric (TE) and other functional electronic materials, chemical doping is commonly employed to tune the carrier density toward an optimal Fermi level and, in turn, maximize the electrical transport. However, in some systems, such as the emerging high-performance $p$-type TE material $\alpha$-MgAgSb, chemical doping is challenging due to its weak chemical bonds and extremely low solubility of heteroatomic dopants, which makes it difficult to increase the hole carrier density and realize the otherwise predictable improvements in the TE power factor. Here, we report a doping-free strategy to enhance the TE performance of $\alpha$-MgAgSb by utilizing a phase-transition-induced self-doping process. Annealing at the phase-transition temperature of 593 K lowers the formation energy of Ag vacancies in the high-temperature $\beta$ phase, and these vacancies are subsequently retained upon cooling back to the $\alpha$ phase. As a result, the hole concentration increases markedly from $4.5\times {10}^{19}$ to $1.3\times {10}^{20}{\mathrm{cm}}^{-3}$, activating multiple valence bands and boosting the room-temperature power factor by $\sim 35\%$ to $30\mathrm{\mu }\mathrm{W}{\mathrm{cm}}^{-1}{\mathrm{K}}^{-2}$. A single-leg device fabricated from the optimized material achieves a high conversion efficiency of 10.7% and a maximum output power of 71.1 mW at $\mathrm{\Delta }T=285\mathrm{K}$. This work demonstrates a viable pathway for enhancing TE performance via phase-transition engineering.

Diamond, an archetype of hardness and brittleness, can nonetheless display striking elastic compliance at the nanoscale, in sharp contrast to its ultrastiff, fracture prone bulk behavior. Despite recent experimental progress, the atomic scale origin of this anomalous elasticity remains unresolved. Here, we uncover a pronounced size- dependent softening in nanodiamond, with the effective axial Young’s modulus decreasing from about 1000 to about 700 GPa as the particle diameter shrinks from 13 to 4 nm. By integrating in situ transmission electron microscopy nanomechanical testing with first principles calculations and molecular dynamics simulations, we show that this stiffness reduction does not arise from the surface atomic layers, which remain comparatively stiff, but instead from weakened bonding in a distinct interfacial region between the surface and the crystalline core. These under-coordinated regions localize strain and accommodate large elastic deformation. The results uncover a previously overlooked interfacial mechanism that governs elasticity in brittle nanomaterials and offer design principles for nanomechanical resonators, quantum devices, and thermal transport applications with tunable stiffness.

The genome contains genetic information essential for a cell’s life. The genome’s spatial organization inside the cell nucleus is critical for its proper function including gene regulation. The two major genomic compartments, euchromatin and heterochromatin, contain largely transcriptionally active and silenced genes, respectively, and exhibit distinct dynamics. In this work, we present a hydrodynamic framework that describes the large-scale behavior of euchromatin and heterochromatin and accounts for the interplay of mechanical forces, active processes, and nuclear confinement. Our model shows contractile stresses from cross-linking proteins lead to the formation of heterochromatin droplets via mechanically driven phase separation. These droplets grow, coalesce, and, in nuclear confinement, wet the boundary. Active processes, such as gene transcription in euchromatin, introduce nonequilibrium fluctuations that drive long-range, coherent motions of chromatin as well as the nucleoplasm and, thus, alter the genome’s spatial organization. These fluctuations also indirectly deform heterochromatin droplets, by continuously changing their shape. Taken together, our findings reveal how active forces, mechanical stresses, and hydrodynamic flows contribute to the genome’s organization at large scales and provide a physical framework for understanding chromatin organization and dynamics in live cells.

Evidence of superconductivity has recently been reported in pressurized nickelates, providing a new platform to explore high-temperature superconductivity. However, detailed experimental characterization of the superconducting properties of nickelates under pressure remains limited and technically challenging. Here, we report the first full temperature-dependent measurements of the upper critical field (${\mu }_0{H}_{c2}$) in pressurized trilayer nickelate ${\mathrm{La}}_4{\mathrm{Ni}}_3{\mathrm{O}}_{10-\delta }$ single crystal, achieved by integrating advanced high-magnetic-field and high-pressure techniques. Remarkably, ${\mathrm{La}}_4{\mathrm{Ni}}_3{\mathrm{O}}_{10-\delta }$ exhibits nearly isotropic superconductivity, with the anisotropic parameter $\gamma$ decreasing monotonically from 1.4 near $T_c$ to 1 at lower temperatures. By applying a two-band model analysis out of plane and in plane ${\mu }_0{H}_{c2}$, we uncover a compensation of anisotropic diffusivity between bands primarily originating from $d_{z^2}$ and $d_{x^2-y^2}$ orbitals, resulting in an exceptionally isotropic superconducting characteristic. These findings indicate the significant contribution of the $d_{z^2}$ orbital to superconductivity in pressurized ${\mathrm{La}}_4{\mathrm{Ni}}_3{\mathrm{O}}_{10-\delta }$ and provide essential constraints for theoretical models of the pairing mechanism in Ruddlesden-Popper nickelates.