  The goal of this work is to show how the thermospin polarization current in a
quantum ring changes in the presence of Rashba spin-orbit coupling and a
quantized single photon mode of a cavity the ring is placed in. Employing the
reduced density operator and a general master equation formalism, we find that
both the Rashba interaction and the photon field can significantly modulate the
spin polarization and the thermospin polarization current. Tuning the Rashba
coupling constant, degenerate energy levels are formed corresponding to the
Aharonov-Casher destructive phase interference in the quantum ring system. Our
analysis indicates that the maximum spin polarization can be observed at the
points of degenerate energy levels due to spin accumulation in the system
without the photon field. The thermospin current is thus suppressed. In the
presence of the cavity, the photon field leads to an additional kinetic
momentum of the electron. As a result the spin polarization can be enhanced by
the photon field.
