TY - JOUR
T1 - Efficient ab initio Migdal-Eliashberg calculation considering the retardation effect in phonon-mediated superconductors
AU - Wang, Tianchun
AU - Nomoto, Takuya
AU - Nomura, Yusuke
AU - Shinaoka, Hiroshi
AU - Otsuki, Junya
AU - Koretsune, Takashi
AU - Arita, Ryotaro
N1 - Funding Information:
This work was supported by Grants-in-Aid for Scientific Research (No. JP19H05825, No. JP19K14654, No. JP18K03442, No. JP18H01158, No. JP16K17735, No. JP17K14336, No. JP20K14423, and No. JP16H06345) from Ministry of Education, Culture, Sports, Science and Technology.
Publisher Copyright:
© 2020 American Physical Society.
PY - 2020/10/8
Y1 - 2020/10/8
N2 - We formulate an efficient scheme to perform a Migdal-Eliashberg calculation considering the retardation effect from first principles. While the conventional approach requires a huge number of Matsubara frequencies, we show that the intermediate representation of the Green's function [H. Shinaoka, Phys. Rev. B 96, 035147 (2017)10.1103/PhysRevB.96.035147] dramatically reduces the numerical cost to solve the linearized gap equation. Without introducing any empirical parameter, we obtain a superconducting transition temperature of elemental Nb (∼10 K), which is consistent with experiment. The present result indicates that our approach has a superior performance for many superconductors for which Tc is lower than O(10) K.
AB - We formulate an efficient scheme to perform a Migdal-Eliashberg calculation considering the retardation effect from first principles. While the conventional approach requires a huge number of Matsubara frequencies, we show that the intermediate representation of the Green's function [H. Shinaoka, Phys. Rev. B 96, 035147 (2017)10.1103/PhysRevB.96.035147] dramatically reduces the numerical cost to solve the linearized gap equation. Without introducing any empirical parameter, we obtain a superconducting transition temperature of elemental Nb (∼10 K), which is consistent with experiment. The present result indicates that our approach has a superior performance for many superconductors for which Tc is lower than O(10) K.
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U2 - 10.1103/PhysRevB.102.134503
DO - 10.1103/PhysRevB.102.134503
M3 - Article
AN - SCOPUS:85093087500
SN - 2469-9950
VL - 102
JO - Physical Review B-Condensed Matter
JF - Physical Review B-Condensed Matter
IS - 13
M1 - 134503
ER -