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Yaqing Xy Wang

Publications and source records attributed to Yaqing Xy Wang.

4 recordsLinked to original sources
arXiv2026

Playing Bayesian games better with separable quantum states than with any classical correlation

Bayesian games, also known as games of incomplete information, are a fruitful arena for exploring the impact of correlations on a set of independent agents (players) via the game equilibria to which they give rise. It was realised some time ago that quantum states shared between the players can lead to new and beneficial equilibria, compared to classical correlation. While until now examples of this effect required an entangled state, here we show that even separable states can create new, genuinely quantum equilibria in games, that are advantageous with respect to all classically correlated equilibria. This shows that non-classical correlations beyond entanglement are indeed a resource, even in otherwise entirely classical situations. Our result brings quantum advantage in games significantly closer to possible realisation.

quant-ph↗
arXiv2026

Optomechanical systems with linear and quadratic position couplings: Dynamics and optimal estimation

We study the dynamics of an optomechanical system consisting of a single-mode optical field coupled to a mechanical oscillator, where the nonlinear interaction includes both linear and quadratic terms in the oscillator's position. We present an analytical solution to this quantum-mechanical Hamiltonian problem by employing the formalism of two-phonon coherent states. Quantum estimation theory is applied to the resulting state of the optical field, with a focus on evaluating the quantum Fisher information with respect to the strength of the quadratic coupling. Our estimation scheme employs balanced homodyne photodetection and demonstrates that the corresponding classical Fisher information can reach the quantum Fisher information limit, with the phase of the local coherent oscillator playing a crucial role.

quant-ph↗
arXiv2021

JDAM -- Jump Diffusion by Analytic Models

Nanoscopic diffusion at surfaces normally takes place when an adsorbate jumps from one adsorption site to the other. Jump diffusion can be measured via quasi-elastic scattering experiments, and the results can often be interpreted in terms of analytic models. While the simplest model of jump diffusion only accounts for intercell jumps between nearest neighbours, recent works have highlighted that models which take into account both intracell and long-range intercell jumps are much needed. Here, we describe a program to compute the analytic lineshape expected from quasielastic scattering experiments, for translational jump diffusion on user-defined lattices. We provide an example of a general hexagonal surface composed of six sublattices, corresponding to the six principle adsorption sites - namely the top, two hollow, and three bridge sites. In that example we include only nearest-neighbour jumps. In addition, we provide a mean to calculate the lineshape for jumps on a hexagonal honeycomb lattice, with jumps up to the 10th nearest neighbour taken into consideration.

physics.comp-ph↗