TY  - JOUR
A1  - Bimonte, Giuseppe
A1  - Haakh, Harald Richard
A1  - Henkel, Carsten
A1  - Intravaia, Francesco
T1  - Optical BCS conductivity at imaginary frequencies and dispersion energies of superconductors
N2  - We present an efficient expression for the analytic continuation to arbitrary complex frequencies of the complex optical and ac conductivity of a homogeneous superconductor with an arbitrary mean free path. Knowledge of this quantity is fundamental in the calculation of thermodynamic potentials and dispersion energies involving type-I superconducting bodies. When considered for imaginary frequencies, our formula evaluates faster than previous schemes involving Kramers-Kronig transforms. A number of applications illustrate its efficiency: a simplified low-frequency expansion of the conductivity, the electromagnetic bulk self-energy due to longitudinal plasma oscillations, and the Casimir free energy of a superconducting cavity.
Y1  - 2010
UR  - http://iopscience.iop.org/1751-8121/
U6  - https://doi.org/10.1088/1751-8113/43/14/145304
SN  - 1751-8113
ER  -