RT Journal Article
T1 Quantum electrodynamic fluctuations of the macroscopic Josephson phase
A1 Kohler, Heiner
A1 Guinea, Francisco
A1 Sols Lucía, Ignacio
AB We study the equilibrium dynamics of the relative phase in a superconducting Josephson link taking into account the quantum fluctuations of the electromagnetic vacuum. The photons act as a superohmic heat bath on the relative Cooper pair number and thus, indirectly, on the macroscopic phase difference /. This leads to an enhancement of the mean squareh/2 i that adds to the spread due to the Coulomb interaction carried by the longitudinal electromagnetic field. We also include the interaction with the electronic degrees of freedom due to quasiparticle tunneling, which couple to the phase and only indirectly to the particle number.The simultaneous inclusion of both the radiation field fluctuations and quasiparticle tunneling leads to a novel type of particle-bath Hamiltonian in which the quantum particle couples through its position and momentum to two independent bosonic heat baths. We study the interplay between the two mechanisms in the present context and find interference contributions to the quantum fluctuations of the phase. We explore the observability of the QED effectsdiscussed here.
PB Elsevier
SN 0003-4916
YR 2004
FD 2004-03
LK https://hdl.handle.net/20.500.14352/50727
UL https://hdl.handle.net/20.500.14352/50727
LA eng
NO Ministerio de Ciencia y Tecnología
NO Ramón Areces Foundation
NO RTN Network of the European Union
DS Docta Complutense
RD 7 abr 2025