Experiments in Quantum Coherence and Computation With Single Cooper-Pair Electronics
Final rept. l Apr 2002-31 Aug 2005
YALE UNIV NEW HAVEN CT DEPT OF APPLIED PHYSICS
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This project is for experimental and theoretical investigations on quantum computation using the single Cooper-pair electronics. We integrate a Cooper-pair box qubit with a high-speed, time-gated quantum readout amplifier, namely the Radio-Frequency Single-Electron Transistor. The physics of single qubits is being studied, in order to identify and reduce the mechanisms of decoherence. We are developing techniques for state manipulation and single-shot readout of qubits, with the goal of demonstrating 1,000 coherent single-bit operations, and to separate errors in control, or measurement-induced dephasing. Another area of investigation is the integration of Cooper-pair boxes with high-Q superconducting microwave resonators, to realize a solid-state version of cavity quantum electrodynamics QED. These resonators are used for engineering coherence times, as a means of entangling charge states, as a mechanism for storing quantum coherence, and as a new type of QND measurement. Devices are fabricated at Yale, and were previously also made under a subcontract to Chalmers University. A closely-coupled theoretical effort, headed by Prof. Steven Girvin at Yale, is examining the phenomenology of dephasing in the Cooper-pair box due to 1f noise and other mechanisms, calculating dephasing and mixing rates for qubits due to the backaction of an RF-SET, developing the circuit QED approach to quantum computing, and comparing architectures for realizing entanglement and quantum logic gates with the Cooper-pair box.
- Electrical and Electronic Equipment
- Electricity and Magnetism
- Quantum Theory and Relativity