Persistent currents in ballistic normal-metal rings
Department of Metal and Semiconductor Physics, NTU «Kharkiv Polytechnic Institute», Kharkiv 61002, Ukraine
Received April 20, 2010
Recent experiments renewed interest in persistent currents in mesoscopic normal-metal rings. We show that in ballistic rings in high magnetic fields the Zeeman splitting leads to periodic current quenching with period much larger than the period of the persistent current. Simple arguments show that this effect might be relevant for diffusive rings as well. Another aim of this paper is to discuss fluctuations of the persistent current due to thermal excitation of high-energy levels. Being observed such fluctuations would witness a coherent state of an
electron system at high temperatures when the persistent current is exponentially suppressed.
PACS: 73.23.Ra Persistent currents; PACS: 73.23.–b Electronic transport in mesoscopic systems; PACS: 73.50.Td Noise processes and phenomena.
Key words: persistent current fluctuations, Zeeman splitting, Luttinger liquid model.