Aharonov endash Bohm oscillations at finite temperature

The Aharonov endash Bohm effect is the quantum interference of charged particles in mesoscopic rings enclosing a magnetic field. The wavefunction acquires a phase due to the field flux φ and gives rise to flux-dependent oscillations in persistent charge currents. The period and amplitude of the oscillations are associated with the properties of the Fermi surface of the elementary excitations. For systems with one Fermi surface the groundstate persistent current has the form of a saw-tooth. The temperature reduces the amplitudes of oscillation by smearing the Fermi surface. The amplitude of higher harmonics decreases faster with T than the fundamental one, changing the saw-tooth to a more sinusoidal form with much smaller amplitude. The controlling parameter is LT/zvF, where L is the length of the ring, vF is the Fermi velocity and z the dressed generalized charge. Our calculations are performed within the framework of Bethe close-quote s ansatz. copyright 1996 American Institute of Physics