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arXiv 1502.07700cond-mat.str-elcond-mat.mtrl-sci
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Weyl和Dirac半金属中的电子冷却

Electronic Cooling in Weyl and Dirac Semimetals

Rex Lundgren, Gregory A. Fiete

摘要:

从电子到声子的能量转移在任何基于Weyl或Dirac半金属的应用中都是重要的考虑因素。在这项工作中,我们分析计算声学声子的冷却功率,即与声学声子相互作用的电子的能量弛豫率,在各种不同的情况下,对于Weyl和Dirac半金属。对于在节点处具有费米能的冷Weyl或Dirac半金属,我们发现电子温度$T_e$随时间按幂律衰减。在重掺杂状态下,$T_e$在远离平衡的时间上线性衰减。在重掺杂的短程无序系统中,我们预测由于电子和声子之间的能量转移增强,声学声子的冷却能力急剧增加。当将外部磁场施加到未掺杂系统时,冷却功率在磁场强度上是线性的,并且$T_e$在时间上具有平方根衰减,在一定值范围内与磁场强度无关。

英文摘要:

Energy transfer from electrons to phonons is an important consideration in any Weyl or Dirac semimetal based application. In this work, we analytically calculate the cooling power of acoustic phonons, i.e. the energy relaxation rate of electrons which are interacting with acoustic phonons, for Weyl and Dirac semimetals in a variety of different situations. For cold Weyl or Dirac semimetals with the Fermi energy at the nodal points, we find the electronic temperature, $T_e$, decays in time as a power law. In the heavily doped regime, $T_e$ decays linearly in time far away from equilibrium. In a heavily doped system with short-range disorder we predict the cooling power of acoustic phonons is drastically increased because of an enhanced energy transfer between electrons and phonons. When an external magnetic field is applied to an undoped system, the cooling power is linear in magnetic field strength and $T_e$ has square root decay in time, independent of magnetic field strength over a range of values.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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