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Electron cooling in three‐dimensional Dirac fermion systems at low temperature: Effect of screening
Author(s) -
Bhargavi K. S.,
Kubakaddi S. S.
Publication year - 2016
Publication title -
physica status solidi (rrl) – rapid research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.786
H-Index - 68
eISSN - 1862-6270
pISSN - 1862-6254
DOI - 10.1002/pssr.201510372
Subject(s) - condensed matter physics , dirac (video compression format) , dirac fermion , fermion , electron , phonon , semimetal , physics , chemistry , quantum mechanics , band gap , neutrino
Hot electron cooling rate P , due to acoustic phonons, is investigated in three‐dimensional Dirac fermion systems at low temperature taking account of the screening of electron–acoustic phonon interaction. P is studied as a function of electron temperature T e and electron concentration n e . Screening is found to suppress P very significantly for about T e < 0.5 K and its effect reduces considerably for about T e > 1 K in Cd 3 As 2 . In Bloch–Grüneisen (BG) regime, for screened (unscreened) case the T e dependence is P ∼ T e 9 ( T e 5 ) and the n e dependence gives P ∼ n e –5/3 ( n e –1/3 ). The T e dependence is characteristic of 3D phonons and n e dependence is characteristics of 3D Dirac fermions. The plot of P / T e 4 vs. T e shows a maximum at temperature T em which shifts to higher values for larger n e . Interestingly, the maximum is nearly same for different n e and T em / n e 1/3 being nearly constant. More importantly, we propose, the n e dependent measurements of P would provide a clearer signature to identify 3D Dirac semimetal phase. (© 2016 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim)