Features of the phase transition in nonequilibrium superconductors with optical pumping

Journal Article · Fri Oct 01 00:00:00 EDT 1976 · Sov. Phys. - JETP (Engl. Transl.); (United States)

OSTI ID:7307879

Elesin, V F

The behavior of a nonequilibrium superconductor near the phase-transition point is investigated. Nonequilibrium quasi-particles are created as a result of absorption of an electromagnetic field with frequency considerably greater than the superconducting gap. The energy distribution of the quasi-particles at zero temperature and at temperatures close to the transition temperature is studied by means of the kinetic equation describing the energy relaxation of the excess quasi-particles with emission of phonons. The dependence of the order parameter on the power of the source and on the temperature is found. It is shown that, above a certain critical power at a fixed temperature (or above a certain temperature at a fixed power of the source), this dependence becomes double-valued, i.e., apart from the usual solution, according to which the gap decreases with increase of pumping power, there appears a second solution, describing an increase of the gap with increased pumping. The existence of the second solution is connected with the coherent character of the interaction of the quasi-particles of the superconductor with the phonons. The stability of the state of a superconductor with optical pumping against small fluctuations is considered and it is postulated that the double-valued dependence of the order parameter on the pumping power may be responsible for the experimentally observed gradual increase in the resistivity of a superconductor with increased pumping.

• Research Organization: Moscow Engineering-Physics Institute
• OSTI ID: 7307879
• Journal Information: Sov. Phys. - JETP (Engl. Transl.); (United States), Journal Name: Sov. Phys. - JETP (Engl. Transl.); (United States) Vol. 44:4; ISSN SPHJA
• Country of Publication: United States
• Language: English

Related Subjects

656101* -- Solid State Physics-- Superconductivity-- General Theory-- (-1987)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ELECTROMAGNETIC FIELDS
EQUATIONS
KINETIC EQUATIONS
OPTICAL PUMPING
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
QUASI PARTICLES
SUPERCONDUCTORS
TEMPERATURE DEPENDENCE
THERMODYNAMIC PROPERTIES
TRANSITION TEMPERATURE