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Junyan Luo

Publications and source records attributed to Junyan Luo.

4 recordsLinked to original sources

Nonreciprocal Relaxation Acceleration

Driven by recent discoveries regarding the quantum Mpemba effect, the anomalous relaxation dynamics of open quantum systems have garnered significant attention. While expediting thermalization to equilibrium has been extensively studied, dynamically accelerating the convergence toward nonequilibrium steady states remains a formidable challenge. In this article, we find a transient engineered nonreciprocal dissipative channel can provide a shortcut that accelerates convergence to the target reciprocal nonequilibrium steady state for the considered two-mode model and initial states. Using interacting bosonic modes, we demonstrate that the temporal activation of a nonreciprocal channel efficiently suppresses prolonged inter-mode energy oscillations, enforcing a rapid, unidirectional thermal dump into the environment. Counterintuitively, we find that this relaxation speedup is robust and independent of the direction of the nonreciprocity. Our results provide a powerful thermodynamic technique for rapid state preparation and cooling in continuous-variable quantum systems, particularly critical for low-temperature quantum information processing.

quant-ph

ID-Eraser: Proactive Defense Against Face Swapping via Identity Perturbation

Deepfake technologies have rapidly advanced with modern generative AI, and face swapping in particular poses serious threats to privacy and digital security. Existing proactive defenses mostly rely on pixel-level perturbations, which are ineffective against contemporary swapping models that extract robust high-level identity embeddings. We propose ID-Eraser, a feature-space proactive defense that removes identifiable facial information to prevent malicious face swapping. By injecting learnable perturbations into identity embeddings and reconstructing natural-looking protection images through a Face Revive Generator (FRG), ID-Eraser produces visually realistic results for humans while rendering the protected identities unusable for Deepfake models. Experiments show that ID-Eraser substantially disrupts identity recognition across diverse face recognition and swapping systems under strict black-box settings, achieving the lowest Top-1 accuracy (0.30) with the best FID (1.64) and LPIPS (0.020). Compared with swaps generated from clean inputs, the identity similarity of protected swaps drops sharply to an average of 0.504 across five representative face swapping models. ID-Eraser further demonstrates strong cross-dataset generalization, robustness to common distortions, and practical effectiveness on commercial APIs, reducing Tencent API similarity from 0.76 to 0.36.

cs.CV

Dynamical multipartite entanglement in a generalized Tavis-Cummings model with XY spin interaction

Multipartite entanglement is a long-term pursuit in the resource theory, offering a potential resource for quantum metrology. Here, we present the dynamical multipartite entanglement, which is in terms of the quantum Fisher information, of a generalized Tavis-Cummings (TC) model introducing the XY spin interaction. Since our model cannot be solved exactly, we theoretically derive and numerically examine the effective description of our model. By the Holstein-Primakoff transformation, we show the bridge from the generalized TC model to the central spin model. Furthermore, the reduced density matrix of the central spins is presented, which is the prerequisite for calculating multipartite entanglement. We also discuss the effect of the temperature, the coupling constant, and the magnetic field on the dynamical multipartite entanglement in the central spin model, where the central spin is initially unentangled. Strong coupling and low temperature are necessary conditions for a genuine multipartite entanglement in the XY model, and together with the magnetic field, they govern the modulation of both the entanglement period and amplitude. Our results unveil the deep link between the TC model and the central spin model, allowing for a better comprehension of their dynamical multipartite entanglement.

quant-ph

Quantum trajectory analysis for electrical detection of single-electron spin resonance

A Monte Carlo simulation on the basis of quantum trajectory approach is carried out for the measurement dynamics of a single electron spin resonance. The measured electron, which is confined in either a quantum dot or a defect trap, is tunnel-coupled to a side reservoir and continuously monitored by a mesoscopic detector. The simulation not only recovers the observed telegraphic signal of detector current, but also predicts unique features in the output power spectrum which are associated with electron dynamics in different regimes.

cond-mat.mes-hall