Magnetization of mesoscopic copper rings: Evidence for persistent currents
Abstract
We have measured the low-temperature magnetization response of 107 isolated mesoscopic copper rings to a slowly varying magnetic flux. At sufficiently low temperature, the total magnetization response oscillates as a function of the enclosed magnetic flux on the scale of half of a flux quantum. The amplitude of the oscillatory moment is ~=1.2×10-15 Am2 and decreases exponentially with increasing temperature on the scale of the correlation energy Ec=hD/(2L)2~=80 mK. This is evidence for a flux-periodic persistent current in each ring of average value 3×10-3eνF/L.
- Publication:
-
Physical Review Letters
- Pub Date:
- April 1990
- DOI:
- 10.1103/PhysRevLett.64.2074
- Bibcode:
- 1990PhRvL..64.2074L
- Keywords:
-
- 73.60.Aq;
- 03.65.Bz;
- 05.30.Ch;
- Quantum ensemble theory