arXiv subjects

Y. L. Zhong

Publications and source records attributed to Y. L. Zhong.

3 recordsLinked to original sources

arXiv2002

Electron dephasing near zero temperature: an experimental review

The behavior of the electron dephasing time near zero temperature, $τ_ϕ^0$, has recently attracted vigorous attention. This renewed interest is primarily concerned with whether $τ_ϕ^0$ should reach a finite or an infinite value as $T \to$ 0. While it is accepted that $τ_ϕ^0$ should diverge if there exists only electron-electron (electron-phonon) scattering, several recent measurements have found that $τ_ϕ^0$ depends only very weakly on temperature, if at all, when $T$ is sufficiently low. This article discusses the current experimental status of "the saturation problem", and concludes that the origin(s) for this widely observed saturation are still unresolved.

cond-mat.mes-hall↗

arXiv2002

Effect of microstructures on the electron-phonon interaction in the disordered metals Pd$_{60}$Ag$_{40}$

Using the weak-localization method, we have measured the electron-phonon scattering times $τ_{ep}$ in Pd$_{60}$Ag$_{40}$ thick films prepared by DC- and RF-sputtering deposition techniques. In both series of samples, we find an anomalous $1/τ_{ep} \propto T^2\ell$ temperature and disorder dependence, where $\ell$ is the electron elastic mean free path. This anomalous behavior cannot be explained in terms of the current concepts for the electron-phonon interaction in impure conductors. Our result also reveals that the strength of the electron-phonon coupling is much stronger in the DC than RF sputtered films, suggesting that the electron-phonon interaction not only is sensitive to the total level of disorder but also is sensitive to the microscopic quality of the disorder.

cond-mat.dis-nn↗

arXiv2001

Effect of annealing on electron dephasing in three-dimensional polycrystalline metals

We have studied the effect of thermal annealing on electron dephasing times $τ_ϕ$ in three-dimensional polycrystalline metals. Measurements are performed on as-sputtered and annealed AuPd and Sb thick films, using weak-localization method. In all samples, we find that $τ_ϕ$ possesses an extremely weak temperature dependence as $T \to 0$. Our results show that the effect of annealing is non-universal, and it depends strongly on the amount of disorder quenched in the microstructures during deposition. The observed "saturation" behavior of $τ_ϕ$ cannot be easily explained by magnetic scattering. We suggest that the issue of saturation can be better addressed in three-dimensional, rather than lower-dimensional, structures.

cond-mat.mes-hall↗