RECENT PROGRESS IN MACROSCOPIC RESONANT TUNNELING AND ITS APPLICATIONS TO QUANTUM INFORMATION PROCESSING
Siyuan Han
The question of whether macroscopic variables obey the laws of quantum mechanics has been debated ever since the earliest days of quantum mechanics.Since early 1980s results from a series of experiments in Josephson junctions and superconducting interference devices(SQUIDs),including macroscopic quantum tunneling,energy level quantization,macroscopic resonant tunneling(MRT),and ac driven coherent dynamics of the phase and flux,strongly support the notion that under proper conditions motions of macroscopic variables are indeed governed by the laws of quantum mechanics.Among many macroscopic quantum phenomena,MRT,which combines two of the most distinctive quantum phenomena-tunneling and energy level-quantization together and does not involve excitation by high frequency fields,is perhaps the strongest evidence demonstrating quantum nature of macroscopic variables.In this article,we review recent development in theory and experiment of MRT.In particular,we show that how dissipation and flux noise affect the rate and line shape of MRT in the double-well of rf SQUID flux qubits and applications of MRT in the ongoing efforts of identifying and understanding mechanisms of decoherence in superconducting qubits for scalable quantum computing.
Progress in physics•Jan 1, 2009•0 citations