Many intrinsically disordered proteins (IDPs) may undergo a phase separation to form a biomolecular condensate. Understanding the behavior of individual molecules within condensates is crucial for characterizing their collective physical properties relevant to biological functions. Here, we investigate the diffusion dynamics of IDPs within protein condensates using molecular dynamics simulations. We find that the proteins exhibit transient subdiffusion due to the viscoelastic nature of the condensates. Under conditions when confinement arises from the finite size of the droplet, the conformation and instantaneous diffusivity of the proteins vary significantly between the droplet interior and the interface with the environment, resulting in non-Gaussian displacement distributions. Moreover, we demonstrate that the structural complexity and intermolecular interactions of proteins modulate the subdiffusive behavior and the relaxation of diffusivity fluctuations. This study highlights key aspects of the heterogeneous structural and dynamical behavior of IDPs within biomolecular condensates.

We investigate how to entangle an atom interferometer and a macroscopic mechanical oscillator to create nonclassical states of the oscillator. This work is done in the context of an experimental-theoretical collaboration that aims to implement the proposal in the paper “Using an Atom Interferometer to Infer Gravitational Entanglement Generation,” written by Carney et al. [PRX Quantum 2, 030330 (2021)]. Here, we propose an entanglement witness (EW), from whose violation the generation of entanglement can be determined. We do this for three scenarios: the noiseless case, when including thermal noise, and with atomic dephasing. Thermal noise can arise from two sources: the first being when the oscillator starts in a thermal state, and the second when a continuous thermal bath is in contact with the oscillator. We find that for the appropriate oscillator quality factor $Q$, violation always exists for any value of coupling $\lambda$ and thermal occupancy $\overline{n}$. Cooling the oscillator to its ground state provides an $O\left(\overline{n}\right)$ improvement in the EW violation than when starting in a thermal state; in this case, we find that couplings of $\lambda ={10}^{-4.5}$ require at least $\sim {10}^{5.2}$ measurements for violation to be observed. For atomic dephasing, we find that EW violation can exist for an atom interferometer with a coherence time of 600 s, which is the parameter our experimental collaborators hope to reach. Finally, we consider how to use magnetic interactions to realize this idea within the context of the torsional pendulum that has been planned for our collaboration.

Complex gene regulatory networks often display emergent simple behavior. Sometimes this simplicity can be traced to a nearly equivalent energy landscape, but not always. Here, we show how a topological theory for stochastic and biochemical networks can predict phase transitions between dynamical regimes, where the simplest landscape paradigm would fail. We demonstrate the utility of this topological approach for a simple gene network, revealing a new oscillatory regime in addition to previously recognized multimodal stationary phases. We show how local winding numbers predict the steady-state locations in the single-mode and bimodal phases, and a flux analysis predicts the respective strengths of the steady-state peaks.

Adaptive derivative-assembled problem-tailored ansatz variational quantum eigensolver (ADAPT-VQE) stands out as a robust algorithm for constructing compact ansätze for molecular simulation. It enables to significantly reduce the circuit depth with respect to other methods, such as unitary coupled cluster singles and doubles, while achieving higher accuracy and not suffering from so-called barren plateaus that hinder the variational optimization of many hardware-efficient ansätze. In its standard implementation, however, it introduces a considerable measurement overhead in the form of gradient evaluations through estimations of many commutator operators. In this work, we mitigate this measurement overhead by exploiting a recently introduced method for energy evaluation relying on adaptive informationally complete generalized measurements (AIMs). Besides offering an efficient way to measure the energy itself, informationally complete (IC) measurement data can be reused to estimate all the commutators of the operators in the operator pool of ADAPT-VQE, using only classically efficient postprocessing. The framework is generic for any IC positive operator-valued measures (POVMs) implementation, and in this work, we demonstrate it’s effectiveness with dilation POVMs. We present the AIM-ADAPT-VQE scheme in detail, and investigate its performance with ${\mathrm{H}}_4$, ${\mathrm{N}}_2$, and 1,3,5,7-octatetraene Hamiltonians and several operator pools. Our numerical simulations indicate that the measurement data obtained to evaluate the energy can be reused to implement ADAPT-VQE with no additional measurement overhead for the systems considered here. In addition, we show that, if the energy is measured within chemical precision, the cnot count in the resulting circuits is close to the ideal one. With scarce measurement data, AIM-ADAPT-VQE still converges to the ground state with high probability, albeit with an increased circuit depth in some cases.

Quasicrystals (QCs) lack three-dimensional periodicity of atomic arrangement but possess long-range structural order, which are distinct from periodic crystals and random systems. Here, we show how the ferromagnetic (FM) order arises in the icosahedral QC (i-QC) on the basis of the Monte Carlo simulation of the Heisenberg model on the Yb lattice of ${\mathrm{Cd}}_{5.7}\mathrm{Yb}$ composed of regular icosahedrons. By finite-size scaling of the Monte Carlo data, we identified the critical exponents of the magnetization, magnetic susceptibility, and spin correlation length, $\beta =0.508\left(30\right), \gamma =1.361\left(59\right)$, and $\nu =0.792\left(17\right)$, respectively. We confirmed that our data satisfy the hyperscaling relation and estimated the other critical exponents $\alpha =-0.376\left(51\right), \delta =3.68\left(23\right)$, and $\eta =0.282\left(65\right)$. These results show a universality class inherent in the i-QC, which is different from those in periodic magnets and spin glasses. In the i-QC, each Yb site at vertices of the regular icosahedrons is classified into eight classes with respect to the coordination numbers of the nearest-neighbor and next-nearest-neighbor bonds. We revealed the FM-transition mechanism by showing that the difference in the local environment of each site is governed by cooperative evolution of spin correlations upon cooling, giving rise to the critical phenomena.

The challenge of controlling the quantum states of matter via light has been at the forefront of modern research on driven quantum matter. We explore the imprinting effects of structured light on superconductors, demonstrating how the quantum numbers of light—specifically spin angular momentum, orbital angular momentum, and radial order—can be transferred to the superconducting (SC) order parameter and control vortex dynamics. Using Laguerre-Gaussian beams, we show that by tuning the quantum numbers and the amplitude of the electric field, it is possible to manipulate a variety of vortex dynamics, including breathing vortex pairs, braiding vortex pairs, vortex droplets, and swirling two-dimensional vortex rings. More complex structures of vortex clusters, such as vortex flake structures, and standing wave motions, also emerge under specific quantum numbers. These results demonstrate the ability to control SC vortex motion and phase structures through structured light, offering potential applications in quantum fluids and optical control of superconducting states. Our findings present a diagram that links light's quantum numbers to the resulting SC vortex dynamics, highlighting the capacity of light to transfer its symmetry onto superconducting condensates. We point out that this approach represents the extension of printing to quantum printing by light in a coherent state of electrons.

We propose an approach to use linearly polarized light to imprint superconducting (SC) vortices. Within the framework of the generalized time-dependent Ginzburg-Landau equations, we demonstrate the induction of the coherent vortex pairs that move in phase with electromagnetic wave oscillations. The overall vorticity of the superconductor remains zero throughout the cycle. Our results uncover rich multiscale dynamics of SC vorticity and suggest optical applications for various types of structured light. In a departure from classical laser printing, the laser printing proposed here can be viewed as quantum printing where we induce quantum excitations in the SC liquid.

A quantum-enhanced telescope (interferometer) can have significant advantages in precisely measuring the angular position of remote objects through sending out ancillary quantum entanglement pairs alongside the large baselines of telescopes. In principle, the larger the baseline, the higher the expected measurement resolution. However, the well-known major problem of photon transmission loss would drastically undermine the practical application of all quantum-enhanced telescopes and optical interferometers that transmit photons along the baseline, especially for the large baselines required for high angular resolution. Here, we propose a photon-transmission-loss-independent quantum-enhanced interferometer that is robust to the transmission loss and keeps its advantages unchanged given whatever large baseline. This removes the well-known barrier to the practical application of quantum-enhanced telescopes. Moreover, in contrast to the previous results of quantum-entanglement-enhanced telescopes requesting sophisticated resources—perfect single-photon entanglement, photon-number-resolving detectors, or quantum memories—our method requires only threshold detectors and tunable coherent-state or two-mode squeezed-state sources, which are mature technologies nowadays, and it does not need any quantum memory. We demonstrate the high performance of our method using Fisher information. For the phase difference of weak light from a remote star, the high-quality result of Fisher information remains constant under arbitrarily large transmission loss, and hence all the advantageous results and the performance of our method are actually independent of transmission loss.

We use the full nonlinear bifurcation theory as a powerful methodology to thoroughly classify and predict the phonon lasing dynamics in optomechanical cavities. We exemplify its scope in the very relevant and so far vaguely explored dynamics of dual-mode phonon lasing when two independent mechanical modes are directly coupled to one optical field. We uncover a plethora of different lasing regimes in a fixed and realistic cavity geometry, including single- and dual-mode lasing, and an example of chaos. All dynamical regimes are unambiguously associated with bifurcations of different natures, which may exhibit both super- and subcritical natures characterizing the often hysteretic behavior of the systems when they are externally driven by a time-varying laser source. Our results, generalizable to any other optomechanical system, open unprecedented pathways to understand and control the formation and dynamics of optomechanical frequency combs.

Preparation of nontrivial quantum states without introducing unwanted excitations or decoherence remains a central challenge in utilizing ultracold atomic systems for quantum simulation. We employ optimal control methods to realize fast, coherent splitting of a one-dimensional Bose-Einstein condensate, achieving negligible classical excitations while preserving quantum correlations. Furthermore, we explore two-step protocols in which controlled classical motion is first induced and subsequently suppressed via tailored control sequences. Our experiments highlight the potential of optimal control for quantum state engineering and dynamical control in many-body quantum systems.

We develop a systematic method for constructing asymptotic quantum many-body scar (AQMBS) states. While AQMBS states are closely related to quantum many-body scar (QMBS) states, they exhibit key differences. Unlike QMBS states, AQMBS states are not energy eigenstates of the Hamiltonian, making their construction more challenging. We demonstrate that, under appropriate conditions, AQMBS states can be obtained as low-lying gapless excited states of a parent Hamiltonian, which has a QMBS state as its ground state. Furthermore, our formalism reveals a connection between QMBS and supersymmetric (SUSY) quantum mechanics. The QMBS state can be interpreted as a SUSY-unbroken ground state.

The high accuracy of the nuclear spin $g$ factor provides a feasible way to construct absolute magnetometry. However, at geomagnetic field, the sensitivity and accuracy of the nuclear spin magnetometer are limited by the ratio of nuclear-spin polarization and the detection efficiency of low-frequency signal. We propose an absolute magnetometer scheme based on the nuclear spin of ${}^3\mathrm{He}$, demonstrating an order-of-magnitude improved sensitivity and onefold improved accuracy compared to a proton magnetometer for the current geomagnetic field standard. We present systematic estimations on the sources of errors within the ${}^3\mathrm{He}$ magnetometer. Through adopting multipass-probe scheme and radio-frequency power stabilization, it is promising to further improve the accuracy of the ${}^3\mathrm{He}$ magnetometer to 100 ppb at geomagnetic field, paving the way to the next generation of geomagnetic field standard.

Distributing entanglement over long distances remains a challenge due to its fragility when exposed to environmental effects. In this work, we compare various entanglement distribution protocols in a realistic noisy fiber network. We focus specifically on two schemes that only require the sending of a nonentangled carrier photon to remote nodes of the network. These protocols rely on optical cnot/cphase gates, and we vary the probability with which they can be successfully performed. Encoding our entangled states in photon polarization, we analyze the effect of depolarizing noise on the photonic states as the carrier passes through the fibers. Building a robust model of photon loss and calculating the distillable entanglement of the noisy states, we find the entanglement distribution rate. We discover that methods involving a separable carrier can reach a higher rate than the standard entanglement distribution protocol, provided that the success probability of the optical cnot/cphase gates is sufficiently high.

We show that cancellation of internal forces together with spatially uncorrelated noise generically enforces a universal $1/s$ scaling of the center-of-mass (COM) diffusivity for polymer segments of contour length $s$, independent of model details. Within an active generalized Rouse-Langevin (A-GRLE) framework for fractal polymers in a viscoelastic bath with weak activity, we derive closed-form links between segment COM motion and the short-time behavior of two-point fluctuations. The same COM law predicts transient $s^{-3}$ tangent-tangent correlations along the contour following a temperature quench. Reanalyzing recent two-locus chromatin tracking, we extract a dynamic COM exponent $\xi =0.77\pm 0.16$, suggesting topological constraints. These results identify model-independent signatures of collective polymer dynamics and clarify that the observed Rouse-like scaling of chromatin loci reflects transient, unentangled dynamics with an inevitable crossover to an entangled regime at longer times.

We report on the observation of highly excited ($\nu \sim 100)$ vibrational states of a trilobite ultralong-range Rydberg molecule in ${}^{87}\mathrm{Rb}$. These states manifest spectroscopically in a regularly spaced series of peaks red-detuned from the $25f_{7/2}$ dissociation threshold. The existence and observed stability of these states require the almost complete suppression of the adiabatic decay pathway induced by the $P$-wave shape resonance of Rb. This stabilization is predicted to occur only for certain Rydberg levels where the avoided crossing between trilobite and $P$-wave-dominated butterfly potential energy curves nearly vanishes, allowing the vibrational states to diabatically traverse the crossing with almost unit probability. This is the first direct measurement of beyond-Born-Oppenheimer physics in long-range Rydberg molecules, and paves the way for future experiments to access and manipulate wave packets formed from high-lying vibrational states.