TY - JOUR
T1 - Ab initio theory of superconductivity in a magnetic field. II. Numerical solution
AU - Linscheid, A.
AU - Sanna, A.
AU - Gross, E. K.U.
N1 - Publisher Copyright:
© 2015 American Physical Society.
PY - 2015/7/8
Y1 - 2015/7/8
N2 - We numerically investigate the spin density functional theory for superconductors (SpinSCDFT) and the approximated exchange-correlation functional, derived and presented in the preceding Paper I [A. Linscheid, Phys. Rev. B 92, 024505 (2015)PRBMDO1098-012110.1103/PhysRevB.92.024505]. As a test system, we employ a free-electron gas featuring an exchange splitting, a phononic pairing field, and a Coulomb repulsion. SpinSCDFT results are compared with Sarma, the Bardeen-Cooper-Schrieffer theory, and with an Eliashberg type of approach. We find that the spectrum of the superconducting Kohn-Sham SpinSCDFT system is not in agreement with the true quasiparticle structure. Therefore, starting from the Dyson equation, we derive a scheme that allows to compute the many-body excitations of the superconductor and represents the extension to superconductivity of the G0W0 method in band-structure theory. This superconducting G0W0 method vastly improves the predicted spectra.
AB - We numerically investigate the spin density functional theory for superconductors (SpinSCDFT) and the approximated exchange-correlation functional, derived and presented in the preceding Paper I [A. Linscheid, Phys. Rev. B 92, 024505 (2015)PRBMDO1098-012110.1103/PhysRevB.92.024505]. As a test system, we employ a free-electron gas featuring an exchange splitting, a phononic pairing field, and a Coulomb repulsion. SpinSCDFT results are compared with Sarma, the Bardeen-Cooper-Schrieffer theory, and with an Eliashberg type of approach. We find that the spectrum of the superconducting Kohn-Sham SpinSCDFT system is not in agreement with the true quasiparticle structure. Therefore, starting from the Dyson equation, we derive a scheme that allows to compute the many-body excitations of the superconductor and represents the extension to superconductivity of the G0W0 method in band-structure theory. This superconducting G0W0 method vastly improves the predicted spectra.
UR - http://www.scopus.com/inward/record.url?scp=84937898010&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.92.024506
DO - 10.1103/PhysRevB.92.024506
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AN - SCOPUS:84937898010
SN - 1098-0121
VL - 92
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 2
M1 - 024506
ER -