Electric field dependence of thermal conductivity of a granular superconductor: Giant field-induced effects predicted
S. A. Sergeenkov
Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research
141980 Dubna, Moscow Region, Russia
PACS: 74.25.Fy, 74.50.+r, 74.80.Bj
Abstract
The temperature and electric field dependence of
electronic contribution to the thermal conductivity (TC) of a
granular superconductor is considered within a 3D model of inductive
Josephson junction arrays. In addition to a low-temperature maximum
of zero-field TC κ (T,0) (controlled by mutual inductance
L0 and normal state resistivity Rn), the model predicts two
major effects in applied electric field: (i) decrease of the
linear TC, and (ii) giant enhancement of the
nonlinear (i.e. ∇ T-dependent) TC with Δ κ (T,E)/κ (T,0) reaching 500% for parallel electric fields
(ET=S0|∇ T| is an "intrinsic" thermoelectric
field). A possiblity of experimental observation of the predicted
effects in granular superconductors is discussed.