We briefly review some properties of ultrasmall superconducting grains. The ground state and the first excited states of the grains are analyzed by studying the parity gap and the spectroscopic gap. Both quantities turn out to be parity dependent and universal functions of the ratio between the level spacing and the BCS gap, delta/Delta. Pairing correlations show up also in the thermodynamic quantities. The presence of a BCS interaction is responsible for an anomaly in the spin susceptibility as a function of temperature. This anomaly persists also in very small grains.
|Titolo:||Properties of ultrasmall superconducting grains|
|Data di pubblicazione:||1999|
|Appare nelle tipologie:||1.1 Articolo in rivista|