arXiv subjects

Yanbo Qiao

Publications and source records attributed to Yanbo Qiao.

3 recordsLinked to original sources

arXiv2026

Spin-Hall devices: spin relaxation spatially separates current injection from Joule dissipation

The stationary state of a spin Hall bar connected to an external load circuit is investigated through a variational approach based on the principle of minimum power dissipation generalized to the two-spin-channel model. The self-consistent distributions of longitudinal and transverse current densities, alongside the corresponding spin and charge accumulations and dissipation power in the resistance, are derived. Surprisingly, it is shown that the Joule dissipation vanishes when the load resistance is placed at a sufficiently large distance compared with the spin-relaxation length. Such a highly non-trivial global stationary state appears as the most striking characteristic of the injection of pure spin current compared with more usual current injection.

cond-mat.mes-hall↗

arXiv2026

A Field-Theoretic Framework for Work Statistics and Universal Scaling in Non-equilibrium Phase Transitions

We develop a field-theoretic framework for work statistics in $O(N)$ models driven through criticality. By analyzing the dynamic renormalization group flow of composite power operators, we find the Kibble-Zurek scaling laws as a natural consequence of the flow, and we derive the scaling of work cumulants relevant to Kibble-Zurek scaling of topological defects from first principles, bypassing heuristic freeze-out argument. This yields the universal scaling $c_n \sim τ_Q^{-α_n}$ for the $n$-th work cumulant density: isolated quantum systems exhibit a scaling of $α_n = p(d+nz)ν/(1+pzν)$, whereas open quantum and classical systems undergo a dimensional collapse to $α_n = pdν/(1+pzν)$. Validated by exact Gaussian solutions and numerical simulations, our theory establishes a foundation for general work statistics far from equilibrium, thereby bridging stochastic thermodynamics and the renormalization group theory.

cond-mat.stat-mech↗

arXiv2026

Scaling Behaviors of Work Cumulants in Slow Isothermal Processes

We study the cumulants of work in a slow isothermal process for gapped systems. Using the Martin-Siggia-Rose-De Dominicis-Janssen (MSRDJ) formalism and the properties of connected correlation functions, we show that in this process, the $n$-th cumulant of work scales as $1/T^{n-1}$ , where $T$ is the time duration. This result holds generally for arbitrary smooth protocols. Furthermore, we derive the coefficients of the cumulants from equilibrium properties. These coefficients are found to be relevant to thermodynamic geometric tensors.

cond-mat.stat-mech↗