Quantum coherence experiments using a hysteretic DC-SQUID

J. Kivioja, T. Nieminen, J. Pekola

One of the advantages of SQUIDs is that they can provide a measurement, which disturbs the measured system very little: the SQUID is inherently not a dissipative element but a reactive one. We investigate the use of hysteretic DC-SQUIDs to measure dynamics of fragile quantum systems. At the first stage we have studied how the cross-over from thermally activated switching into macroscopic quantum tunnelling is modified in SQUIDs with low critical current due to the quantized energy levels in the SQUID potential. This work is done in collaboration with Dr. Olivier Buisson’s group at CNRS Grenoble.