Detection of geometric phases in superconducting nanocircuits
When a quantum-mechanical system undergoes an adiabatic cyclic evolution, it acquires a geometrical phase factor' in addition to the dynamical one; this effect has been demonstrated in a variety of microscopic systems. Advances in nanotechnology should enable the laws of quantum dynamics to be tested at the macroscopic level, by providing controllable artificial two-level systems (for example, in quantum dots and superconducting devices). Here we propose an experimental method to detect geometric phases in a superconducting device. The setup is a Josephson junction nanocircuit consisting of a superconducting electron box. We discuss how interferometry based on geometrical phases may be realized, and show how the effect may be applied to the design of gates for quantum computation.
Falci
G
Dipartimento di Metodologie Fisiche e Chimiche, Universita di Catania, Italy. gfalci@dmfci.ing.unict.it
Fazio
R
Palma
GM
Siewert
J
Vedral
V