Finite-temperature linear conductance from the Matsubara Green's function without analytic continuation to the real axis

Physical Review B - Condensed Matter and Materials Physics

Volumn 82, Issue 12, 2010, Pages

  Karrasch, C ^a   Meden, V ^a   Schonhammer K ^b  

^a RWTH AACHEN UNIVERSITY   (Germany)

^b UNIVERSITY OF GÖTTINGEN   (Germany)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 77957737611     PISSN: 10980121     EISSN: 1550235X     Source Type: Journal    
DOI: 10.1103/PhysRevB.82.125114     Document Type: Article

References (23)

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16. ′ (i ω n) turns out to be independent of those details, the local density of states is rather "unstable." The latter is illustrated in Fig., where the mesh employed is the one detailed in Ref.. Following the notation of this Ref., the discretization parameters { N, N 0, S, A } of the upper panel are given by T / Γ = 0.05: { 41, 11, 2, 2 }, T / Γ = 0.2: { 41, 12, 2, 2 }, and T / Γ = 0.8: { 41, 20, 2, 2 }, and those of the lower panel read T / Γ = 0.05: { 61, 15, 2, 2 }, T / Γ = 0.2: { 61, 22, 2, 2 }, and T / Γ = 0.8: { 61, 61, 2, 2 }.
17. ′ (i ω) can be computed in a stable way for arbitrary arguments ω except those close to the real axis (ω < ω 0).
18. If one implements the FRG in Keldysh space, the finite-temperature linear-response (as well as the nonequilibrium) conductance of the SIAM can be obtained without carrying out an analytic continuation (Ref.). The structure of the FRG flow equations, however, is far more complex in the Keldysh than in the Matsubara formalism. If one is interested in linear response only, the latter thus provides the simplest framework to study more complex geometries.
19. Standard NRG is a well-established numerical tool to compute low-energy equilibrium properties of quantum impurity systems. A detailed introduction to this method can be found in Ref..
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22. More precisely, we employ the so-called "approximation 1" in the notation of Ref..
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