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Qicheng Tang

Publications and source records attributed to Qicheng Tang.

20 records · Page 2Linked to original sources

Critical Scaling Behaviors of Entanglement Spectra

We investigate the evolution of entanglement spectra under a global quantum quench from a short-range correlated state to the quantum critical point. Motivated by the conformal mapping, we find that the dynamical entanglement spectra demonstrate distinct finite-size scaling behaviors from the static case. As a prototypical example, we compute real-time dynamics of the entanglement spectra of a one-dimensional transverse-field Ising chain. Numerical simulation confirms that, the entanglement spectra scale with the subsystem size $l$ as $\sim l^{-1}$ for the dynamical equilibrium state, much faster than $\propto \log^{-1} l$ for the critical ground state. In particular, as a byproduct, the entanglement spectra at the long time limit faithfully gives universal tower structure of underlying Ising criticality, which shows the emergence of operator-state correspondence in the quantum dynamics.

cond-mat.stat-mech↗

Influence of hydrogen on electron-phonon coupling and intrinsic electrical resistivity in zirconium: a first-principles study

The paper presents the first-principle calculation of the electron-phonon coupling and the temperature dependence of the intrinsic electrical resistivity of the zirconium-hydrogen system with various hydrogen concentrations. The nature of the anomalous decrease in the electrical resistivity of the Zr-H system with the increase of hydrogen concentration (at the high concentrations of H/Zr$>$1.5) was studied. It was found that the hydrogen concentration, where the resistivity starts to decrease, is very close to the critical concentration of the $δ-\varepsilon$ phase transition. It was shown that the tetragonal lattice distortion due to the $δ-\varepsilon$ phase transition of the Zr-H system eliminates imaginary phonon frequencies and the strong electron-phonon coupling of the $δ$ phase and, as a result, leads to the reduction of the electrical resistivity of the Zr-H system at a high hydrogen concentration.

cond-mat.mtrl-sci↗