Abstract
Effects of quantum phase fluctuations on the critical temperature
T
c of Josephson-coupled layered superconductors are considered.
T
c is shown to decrease nonlinearly with increasing charge fluctuations. The results obtained for the critical temperature by applying the self-consistent mean field method reveal no phase transition from superconducting state to normal metal for a finite value of charging energy. The destruction of the long range phase coherence appeared to occur at asymptotically large values of self-capacitance charging. For the weak quantum phase fluctuations limit,
T
c is obtained to be vary in the interval of
T
c
*<
T
c<
T
c
(2), where
T
c
(2) is the critical temperature for a single superconducting layer evaluated by the mean field theory, and
T
c
* is the temperature when the phase coherence between the nearest neighboring layers is lost. Since
T
c approaches
T
c
* with vanishing interlayer tunneling integral
J
⊥. Calculation of the dependence of the transverse stiffness on the charging energy is carried out at
T=0. The reentrance found can in principle occur at a sufficiently large value of the interlayer tunneling integral
J
⊥>
J
⊥
cr=
k
T
c
(2), where
J
⊥
cr≈
k
T
c
(2) is the value of
J
⊥ when the superconductor normal metal phase transition takes place. However, the condition
J
⊥≥
k
T
c
(2) contradicts to the existence of the Josephson coupling between superconducting layers.