Experiments in Quantum Coherence and Computation with Single Cooper-Pair Electronics
Abstract
The aim of this project is to measure the coherence time of charge states in the single Cooper-pair box, which is a candidate system for realizing a solid-state, electronic qubit for quantum computation. Techniques for the control and measurement of these states are being developed and applied to demonstrate sufficient coherence to allow quantum computabon. In the past year, we have observed coherent two-level system behavior for our Cooper-pair box qubits through microwave spectrsocopy. We have obtained a worst case estimate of the decoherence time, under conditions of continuous measurement and maximal sensitivity to 1/f charge noise, of about 1 nanosecond. More interestingly, we have also been able to observe a very long (1 microsecond) inelastic lifetime for the qubit to decay into its ground state. This sets an interesting maximal limit on the coherence which could then be almost 1 million times longer than the single-bit operation time, and indicates that the dissipation in Al/AlOx/Al junctions can be very low. In addition, this long lifetime is present in the presence of the measurement by the RF-SET, and implies that high-fidelity single-shot measurements of the qubit state will be possible with this approach.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 30, 2002
- Accession Number
- ADA414679
Entities
People
- Robert J. Schoelkopf
Organizations
- Yale University