A direct measurement method of quantum relaxation time

• 作 者: Peng Zhang Haoqi Tang Chuanchuan Gu Hong Wang Guangfu Luo Yalin Lu X.-D.Xiang
• 机 构: Department of Materials Science and Engineering & Department of Physics, Southern University of Scie
• 出 处: 国家科学评论（英文版）
• 发表日期: 2021年4期
• 关键词: quantum relaxation time plasma resonance dielectric loss function

The quantum relaxation time of electrons in condensed matters is an important physical property,but its direct measurement has been elusive for a century.Here,we report a breakthrough that allows direct determination of quantum relaxation time at zero and non-zero frequencies using optical measurement.Through dielectric loss function,we connect bound electron effects to the physical parameters of plasma resonance and find an extra term of quantum relaxation time from inelastic scattering between bound electrons and conduction electrons at non-zero frequencies.We demonstrate here that the frequency-dependent inelastic polarization effect of bound electrons is the dominant contribution to quantum relaxation time of conduction electrons at optical frequencies,and the elastic polarization effect of bound electrons also dramatically changes the plasma resonance frequency through effective screening to charge carriers.