Quantum Physics
We present a method for characterizing polarization fiber channels carrying broadband quantum signals, where narrowband filtering would waste photon flux. Wavelength-dependent polarization mode dispersion (PMD) maps each input state to a…
Calibrating a superconducting transmon chip is a sequential decision problem under noise, drift, and a finite budget: an expert must choose experiments, read ambiguous plots, judge fit quality, and revise stale beliefs as the chip drifts.…
The classical Kolmogorov--Arnold representation theorem states that any continuous multivariate function can be exactly decomposed into a finite composition of univariate continuous functions and addition operations. This foundational…
The time evolution of non-Hermitian systems is generally nonunitary. Dynamics governed by time-dependent non-Hermitian Hamiltonians lead to a variety of novel phenomena, one of which is state amplification or suppression induced by the…
Autonomous coding agents perform well on many conventional programming tasks, but scientific computing demands a rigorous validation paradigm that extends beyond simple functional test completion: generated code must preserve physical…
Quantum state tomography is an essential tool for characterizing quantum systems and underpins nearly every experimental realization of quantum technologies. Conventional tomography relies on performing a sequence of projective measurements…
We study spin effects in twisted-electron propagation through the entrance or exit region of an axially symmetric magnetic coil. Starting from the Foldy-Wouthuysen reduction of the Dirac equation, we derive a paraxial spinor equation in…
We derive parent Hamiltonians in terms of oscillator operators for multimode bosonic cat resource states. The construction separates a universal branch Hamiltonian, which confines each mode to the coherent-state support $…
We propose the first error-tolerant secure key leasing (SKL) for public-key encryption. As with SKL in prior works, our protocol consists of a lessor and lessee. In the protocol, the lessor encodes its secret key into quantum states and…
While typical online estimation methods can estimate the multiparameter dynamics of many systems, they may not be sufficient for a system with highly noisy measurement and rapid detection rate. In this paper, we create a hybrid estimation…
For the precision-based measurements, Mach-Zehnder interferometry is a widely used technique. There are various ways to enhance the precision of Mach-Zehnder interferometer (MZI), e.g., having a non-classical input state is one of the ways…
Noisy-metrology theory characterizes decoherence by its two-point correlation function, equivalently the single-atom coherence time or noise spectrum. We show this is insufficient for entangled probes: two collective baths with identical…
We propose two-stage optimized strategies for full-period optical phase estimation with single-mode Gaussian states and Gaussian measurements under a fixed energy constraint. In the first stage (Stage I), displaced squeezed probes and…
Three-level systems exhibit quantum interference effects absent in two-level systems, making them important for quantum optics. Here, we study the coherent interaction of a Lambda-type three-level system with free electrons shaped by…
Quantum error mitigation (QEM) is usually benchmarked by expectation-value accuracy, but many near-term workflows use those values only to make downstream choices such as argmin selection, ranking, top-k filtering, optimizer-step…
As a hallmark of nonclassical light, squeezed light is of profound theoretical interest and holds broad practical promise for emerging quantum technologies. In this work, we investigate steady-state optical quadrature squeezing in the open…
We propose a two-way entanglement-based quantum secure direct communication (QSDC) protocol in which information is encoded as the value of a continuously tunable parameter and decoded from empirically estimated joint-outcome histograms…
Singular interactions can reshape quantum spectra by changing admissible wavefunction domains. In this study, we investigate this mechanism in the Klein--Gordon equation for a non-central Schi\"oberg-type hyperbolic potential with double…
We propose a quantum algorithmic protocol for calculating astrophysical opacities. Our implementation uses first- and second-quantized representations of interacting electronic and photonic subsystems and Hamiltonian simulation via the…
A solvable charger--battery model is introduced in which quantum coherence controls both where a quantum battery's charge is stored and how robustly it survives noise. Charging converts the charger's coherence into charger--battery…