Holography-inspired teleportation has recently emerged as a significant area of research in quantum many-body systems. In this work, we investigate the effects of $\mathcal{PT}$-symmetric nonunitary deformations on the traversability of the wormhole-inspired teleportation protocol modeled by coupled Sachdev-Ye-Kitaev (SYK) systems prepared in a thermofield double state bath. By introducing balanced gain and loss terms to the boundary Hamiltonians, we identify a phase transition driven by spectral exceptional points, where the real energy eigenvalues of the effective Hamiltonian coalesce and bifurcate into complex-conjugate pairs. We demonstrate that the $\mathcal{PT}$-broken phase acts as an amplifier, enabling exponential growth in the norm of the teleported signal while preserving the causal time window for the wormhole's traversability. A statistical study of disorder realizations reveals that the critical non-Hermiticity threshold ${\gamma }_c$ follows a log-normal distribution, reflecting the sensitivity of the transition to the microscopic level spacing of the chaotic SYK spectrum. Furthermore, we observe a “purification” effect deep in the broken phase, where the teleportation channel acts as an entanglement distiller, yielding near-perfect teleportation fidelity for postselected states. Our results suggest that the non-Hermitian topology can be harnessed to enhance holographic quantum communication, providing a robust mechanism for signal amplification in noisy, minimal quantum many-body systems.

The Maximum Independent Set (MIS) problem on unit-disk graphs is an NP-hard problem that can be naturally encoded on Rydberg atom systems. While existing mapping schemes enable the encoding of arbitrary graphs, current two-dimensional (2D) embedding approaches have an $O\left(n^2\right)$ atom overhead, limiting the size of problems solvable on near-term hardware. In this work, we present a scalable scheme that maps the MIS problem on arbitrary graphs onto programmable three-dimensional (3D) arrays of Rydberg atoms. By utilizing the extra degree of freedom provided by the third dimension, we develop a graph-reduction algorithm that embeds any graph into a 3D unit-disk graph. We show this embedding requires an overhead of $O(min\{m\sqrt{n},n^2\})$ atoms, where $n$ and $m$ denote the number of vertices and edges of the original graph. Furthermore, we prove that our embedding scheme is optimal for both bounded-degree graphs and dense graphs. Benchmarks on 3-regular, Erdős-Rényi, SAT-derived graphs, and standard MIS benchmark sets demonstrate that the required atom count is one to two orders of magnitude lower than state-of-the-art 2D schemes. Our work establishes a practical route toward solving large-scale, classically intractable MIS instances on near-term Rydberg quantum processors.

Gaussian quantum channels constitute a pivotal physical framework for characterizing the dynamics of Gaussian quantum states. Extensive scholarly attention has been devoted to the estimation of parameters associated with Gaussian channels. However, while previous research has predominantly focused on parameter estimation within inertial frames, the noninertial scenario, particularly in the context of the Unruh effect, remains largely unexplored. In this paper, we analyze the impact of the Unruh effect on the estimation precision of Gaussian channel parameters, with a specific focus on thermal attenuator and thermal amplifier channels. Our findings reveal that the Unruh effect significantly degrades the precision of single-parameter estimation for Gaussian channel parameters when employing both the input coherent state and squeezed vacuum state. For the two-parameter estimation, we further demonstrate that the quantum Cramér-Rao bound serves as an asymptotically achievable precision limit. Consistent with the single-parameter case, the Unruh effect exerts a detrimental impact on the precision of two-parameter estimation. Notably, heterodyne measurement is near-optimal for both single- and two-parameter estimation in the limit of high acceleration or large thermal mean numbers. These results provide crucial theoretical insights and practical guidance for advancing quantum parameter estimation in a relativistic context.

Adopting explicitly correlated Kołos-Wolniewicz-type basis functions, the Born-Oppenheimer potential curves of a number of excited $\mathrm{\Sigma }$ states of the hydrogen-antihydrogen system $\left(\mathrm{H}\overline{\mathrm{H}}\right)$ were calculated for both, even and odd, Q symmetries, including also free positronium states. It is demonstrated that the excited leptonic states support rovibrational states with energies close to the ground-state dissociation threshold. As a consequence, the excited leptonic states need to be considered in theoretical treatments of ground-state $\mathrm{H}\text{–}\overline{\mathrm{H}}$ collisions.

We characterize Feshbach resonances in all isotopologs of the $\mathrm{Li}-\mathrm{Li}$ system with improved interaction potentials. Starting from spectroscopically accurate Morse/long-range (MLR) potential-energy curves for the singlet ($X{}^1\mathrm{\Sigma }^{+}$) and triplet ($a{}^3\mathrm{\Sigma }^{+}$) electronic states of ${\mathrm{Li}}_2$, we apply small phenomenological inner-wall adjustments [following Julienne and Hutson, Phys. Rev. A 89, 052715 (2014)] and fit the resulting potentials to threshold measurements for the ${}^6\mathrm{Li}-{}^6\mathrm{Li}$ and ${}^7\mathrm{Li}-{}^7\mathrm{Li}$ isotopologs, including binding energies, scattering lengths, and Feshbach resonance positions. Using the optimized potentials in coupled-channel scattering calculations, we predict and characterize $s$-wave Feshbach resonances in the ${}^6\mathrm{Li}-{}^7\mathrm{Li}$ isotopolog. In its lowest-energy hyperfine channel, all resonances are narrow ($\sim 0.01-0.1\mathrm{G}$), strongly closed-channel dominated, and predominantly triplet in electronic spin character, in marked contrast to the homonuclear systems. These results provide a foundation for designing Raman optical-transfer pathways to produce ultracold ${\mathrm{Li}}_2$ molecules in deeply bound rovibrational levels of both the $X{}^1\mathrm{\Sigma }^{+}$ and $a{}^3\mathrm{\Sigma }^{+}$ potentials across all three isotopologs.

Coherent radiation from laser-driven electron beams can serve as a light source. In this work, we investigate the coherent radiation emitted by a multielectron system interacting with a plane-wave electromagnetic pulse in the framework of strong-field QED. Using the density matrix formalism, we generalize the quantum description of the initial electron wave packets from pure states (considered in previous works) to mixed states, and derive the corresponding radiation energy spectrum. Our results reveal that the indistinguishability of electrons may suppress the radiation coherence and that the cutoff frequency of the coherent radiation is strictly limited by the position uncertainty of the wave packets. We also further explore the feasibility of introducing quantum corrections to the classical electrodynamic description of coherent radiation from multielectron systems. This work provides insights for the development of coherent Compton light sources driven by intense lasers.

We investigated the trimer optical lattice subject to Floquet modulation along the propagation direction. Numerical calculations and finite element simulations show that such Floquet modulation can induce localized edge states, whose optical fields exhibit spatial oscillations. Quasienergy band analysis further indicates that this oscillatory behavior originates from Floquet topological modes (FTMs). More importantly, it is demonstrated that these FTMs can continuously evolve into the Bloch topological modes induced by periodic static structural modulation, all while maintaining an open quasienergy gap. These findings elucidate the intricate mechanisms for controlling topological modes in systems with both Bloch and Floquet periodicity and provide physical insights into topological phase transitions in trimer lattices driven by unconventional gap-closing mechanisms.

We report second-order intensity correlations $g^{\left(2\right)}\left(\tau \right)$ of directional midinfrared emissions from sodium vapor under bichromatic continuous-wave excitation. Directional emission at $2.34\mu \mathrm{m}$ in the forward direction and at $2.21\mu \mathrm{m}$ in both forward and backward directions exhibits $g^{\left(2\right)}\left(0\right)$ values that exceed unity yet remain well below the thermal limit of 2, indicating subthermal photon bunching characteristics of a multimode collectively driven process rather than purely independent amplified spontaneous emission. Cross-correlation measurements reveal that the counterpropagating $2.21\text{−}\mu \mathrm{m}$ beams are positively correlated, demonstrating dynamic coupling between the two emission channels. Persistent oscillations in $g^{\left(2\right)}\left(\tau \right)$, observed across a broad range of pump powers, shift systematically to higher frequencies with increasing excitation power, consistent with ac Stark shifts of hyperfine sublevels. Together, these observations establish that the emission arises from a phase-matched, continuous-wave collective process combining features of mirrorless lasing and amplified spontaneous emission, with long-range dipole coherence and velocity-selective coupling governing the photon statistics and the forward-backward emission symmetry. The experiment uses a 10-cm buffer-gas-free sodium vapor cell under bichromatic excitation at 589.2 and 569.0 nm; the emitted midinfrared light is detected in a Hanbury Brown–Twiss configuration. The demonstrated backward emission is of particular interest for applications in laser guide star generation and mesospheric remote sensing, where understanding the statistical properties of the emitted light is essential for optimizing sodium-based light sources.

Control of the temporal waveform of photons produced during spontaneous emission from single quantum emitters provides a crucial tool in the establishment of hybrid quantum systems, the optimization of quantum state transfer protocols, and the mitigation of effects due interferometric instability for network architectures based on flying qubits. We describe a method to generate photons of any temporal waveform from emitters of any excited state lifetime, limited only by the timing resolution of control hardware. We show how the temporal waveform of photons can be controlled by deterministically varying the population of an excited state which undergoes spontaneous emission. Our broadly applicable approach has only two requirements for a candidate quantum emitter: modulation of the (1) amplitude and (2) relative phase of a field coupling a ground state to the excited manifold. We detail how to identify optimal excitation pulses by employing variational algorithms to feed back on atomic populations. Additionally, we develop quantum Monte Carlo based tools to determine photon-number statistics and establish techniques to identify optimal excitation strengths and post-selection thresholds for photon generation protocols. We situate our work in the context of other prior research on bespoke single-photon sources and networking including post-emission pulse shaping, temporal gating, and cavity-based methods. In comparison, our free-space process has greater flexibility in producing any waveform, requires less infrastructure, and can be readily applied across a wide range of quantum emitters. We discuss the applications and limits of this technique, including how increasing photon emission probabilities affects achievable temporal-mode overlap fidelities between emitted and target photon waveforms.

Generalizations of Bell's framework to causal networks have yielded foundational insights and applications, including the use of interventions to enhance the detection of nonclassicality in scenarios with communication. Such interventions, however, become uninformative when all observable variables are space-like separated. To address this limitation, we introduce the latent splitting procedure, a generalization of interventions to quantum networks in which controlled manipulations are applied to latent quantum systems. We show that latent splitting enables the detection of nonclassicality by combining observational and interventional data even when conventional interventions fail. Focusing on the triangle network, we derive analytical witnesses that robustly certify nonclassicality, including nonlinear inequalities for minimal binary-variable scenarios and extensions of the nonclassical region of previously proposed experiments.

Quantum machine learning integrates quantum features such as superposition and entanglement into learning processes, offering the potential to outperform classical methods in certain tasks. Among these approaches, quantum reservoir computing (QRC) has attracted considerable attention due to its simple structure and strong performance. However, existing QRC models remain limited in high-dimensional nonlinear representation and scalability, thereby constraining their computational performance in practical applications. In this work, we propose a quantum reservoir architecture that employs hyperentangled states to expand the effective dimensionality of the reservoir, enabling high-dimensional quantum information to be encoded within a small number of physical carriers. Based on this architecture, we design an optical scheme that serves as a physically realizable reservoir layer for QRC. Numerical simulations on high-dimensional nonlinear regression tasks, including the nonlinear autoregressive moving average of order 30 and Mackey-Glass tasks, demonstrate that the proposed architecture achieves high prediction accuracy and strong nonlinear mapping capability, thus paving a way toward scalable, high-dimensional, and efficient QRC.

Entanglement detection is of crucial significance to quantum technologies and yet remains a difficult enterprise. The positive partial transposition (PPT) and moment-based criteria are two key methods of entanglement detection. Among them, in an ideal setup, the PPT criterion can detect a greater volume of states but is more expensive, as it requires state tomography. We carry over the comparison of these two processes to a realistic situation with inaccurate detectors, in particular considering those that involve additional and lost counts. Considering Werner states, we find that the occurrence of additional counts does not result in false positives—declaring a separable state as entangled—for both methods. Additionally, we demonstrate that the PPT criterion detects a greater number of entangled Werner states compared to the moment-based method in this nonideal scenario. Moreover, we find that detectors troubled by lost counts may lead to false positives in both methods. However, the moment-based criterion is error free when the efficiency of the detectors is not significantly low; on the other hand, if the PPT criterion is used, a small deviation from the perfection of detectors can result in a wrong conclusion. The performance of the two criteria is further compared with both linear and nonlinear witness operators for Werner states. Nonlinear witness operators are found to be less accurate, whereas the linear witness achieves the same accuracy as the PPT criterion followed by tomography. Finally, we consider Bell mixture states and two-qubit pure entangled states mixed with white noise. For both, we observe that no erroneous detection of entanglement occurs only in the presence of additional counts, whereas false detection arises in the presence of lost counts for both the PPT and $p_3$-PPT criteria.

We analyze the use of the Solovay-Kitaev (SK) algorithm to generate an ensemble of one-qubit rotations over which to perform randomized compilation. We perform simulations to compare the trace distance between the quantum state resulting from an ideal one-qubit $R_Z$ rotation and discrete SK decompositions. We find that this simple randomized gate synthesis algorithm can reduce the approximation error of these rotations in the absence of gate errors in simulation by at least a factor of 2 compared to a naive gate synthesis algorithm. We test the technique under the effects of a simple coherent noise model and find that it can mitigate coherent noise. We also run our algorithm on Sandia National Laboratories' QSCOUT trapped-ion device and find that randomization is able to help in the presence of realistic noise sources.

We extend the quantum-feature kernel framework, which relies on measurements of graph-dependent observables, along three directions. First, leveraging neutral-atom quantum processing units, we introduce a scheme that incorporates attributed graphs by embedding edge features into atomic positions and node features into local detuning fields of a Rydberg Hamiltonian. We demonstrate both theoretically and empirically that local detuning enhances kernel expressiveness. Second, in addition to the existing quantum evolution kernel ($\mathrm{QEK}$), which uses global observables, we propose the generalized-distance quantum-correlation ($\mathrm{GDQC}$) kernel, based on local observables. While the two kernels show comparable performance, we show that $\mathrm{GDQC}$ can achieve higher expressiveness. Third, instead of restricting to observables at single time steps, we combine information from multiple stages of the quantum evolution via pooling operations. Using extensive simulations on two molecular benchmark datasets, MUTAG and PTC_FM, we find (a) $\mathrm{QEK}$ and $\mathrm{GDQC}$ perform competitively with leading classical algorithms, and (b) pooling further improves performance, enabling quantum-feature kernels to surpass classical baselines. These results show that node-feature embedding and kernel designs based on local observables advance quantum-enhanced graph machine learning on neutral-atom devices.

Large, three-dimensional (3D) trapped-ion crystals offer improved sensitivity in quantum sensing protocols, and are expected to be implemented as platforms in near-future experiments. However, numerical techniques used to study the laser cooling of such crystals are inefficient as the number of ions, $N$, in the crystal increases. Here we develop a powerful numerical framework to simulate laser cooling of up to ${10}^5$ ions stored in a Penning trap. We apply this framework to characterize and optimize the cooling of ellipsoidal 3D crystals. We document pathways to enhanced cooling based on the addition of an axial component to the potential-energy-dominated $\mathit{E}\times \mathit{B}$ modes. Furthermore, we observe greatly enhanced cooling of the perpendicular kinetic energy to below 1 mK in prolate ion crystals, enabling a simplified cooling beam setup for such crystals. We propose specific values of trap and laser beam parameters which lead to optimal cooling in a variety of examples. This work illustrates the feasibility of preparing large 3D crystals for high-sensitivity quantum science protocols, motivating their use in future experiments.

Motivated by the realistic scenario in which impurity incorporation can induce lattice deformation, we investigate the cooperative control of solid-state high-harmonic generation (HHG) by external strain and donor-like local potential modulation within a one-dimensional time-dependent Schrödinger equation (TDSE) framework. Strain reshapes the electronic structure by modifying the band gap, effective mass, and transition dipole moment, leading to substantial changes in HHG intensity and chirp. To provide qualitative comparison with realistic materials, strain effects are further analyzed using first-principles-based semiconductor Bloch equation calculations. We identify two distinct strain classes: tensile strain narrows the band gap in wurtzite ZnO, whereas compressive strain narrows it in monolayer black phosphorus, resulting in opposite strain dependences of the HHG response. Resolving the spectrum relative to the minimum band gap reveals three regimes: intraband-dominated subgap harmonics, dephasing-sensitive band-edge harmonics, and strain-enhanced above-gap emission. The dephasing time $T_2$ primarily affects the band-edge region, while strain robustly governs the plateau intensity. Impurity-induced local potential modulation introduces additional excitation channels that cooperate with strain, particularly enhancing higher-order harmonic emission. These results clarify the complementary roles of strain, impurity-induced local potential modulation, and dephasing in tailoring strong-field emission in solids.

Angular momentum coupling manifests widely in diverse physical systems, underpinning the emergent properties and collective dynamics across different scales. The tidal locking, which originates from the synchronization of rotational and orbital motions, has far-reaching impacts in celestial mechanics, reflecting fundamental processes of angular momentum transfer, energy dissipation, and evolution toward dynamical equilibrium. However, its counterpart in mesoscopic quantum fluids has remained largely unexplored. Here we demonstrate the emergence of quantum tidal locking in Bose-Einstein condensates undergoing central force motion in an anharmonic potential. The condensate follows a well-defined orbital trajectory in a static trap and experiences an effective rotating potential induced by the trap anharmonicity. The sustained geometric squeezing continuously deforms the condensate and drives a self-organized synchronization process, in which the intrinsic rotation gradually locks to the orbital motion. Numerical simulations further reveal the formation of a ring-shaped vortex array over longer timescales, arising from the coherent evolution of the rotating matter wave during the locking dynamics. Our findings establish quantum tidal locking in mesoscopic systems as a robust self-organized mechanism for generating and stabilizing circulating states.

We theoretically investigate the thermodynamic properties of a quasi-one-dimensional single-component dipolar Fermi gas at finite temperatures. A self-bound fermionic droplet can be achieved by exchange correlations with long-range dipole-dipole interactions under quasi-one-dimensional confinement, where the interaction can be tuned by tilting the dipoles along the system coordinate. Using the Hartree-Fock approximation, we show how the liquid-gas phase transition occurs in this system and elucidate the finite-temperature phase structure consisting of a gas phase, liquid phase, gas-liquid coexistence phase, and spinodal phase. We also discuss its similarity to the liquid-gas phase transition in nuclear matter through a comparison with phenomenological models. By examining the experimental conditions for realizing self-bound fermionic droplets, we find that microwave-shielded fermionic polar molecules are promising candidates. Our results will be useful for an interdisciplinary understanding of self-bound fermionic matter as well as an analog quantum simulation of nuclear systems.