TY - JOUR
AU - Tsai, J. S.
AB - A nanometre-scale superconducting electrode connected to a reservoir via a Josephson junction constitutes an artificial two-level electronic system: a single-Cooper-pair box. The two levels consist of charge states (differing by 2e, where e is the electronic charge) that are coupled by tunnelling of Cooper pairs through the junction. Although the two-level system is macroscopic, containing a large number of electrons, the two charge states can be coherently superposed
1,2,3,4
. The Cooper-pair box has therefore been suggested
5,6,7
 as a candidate for a quantum bit or ‘qubit’—the basic component of a quantum computer. Here we report the observation of quantum oscillations in a single-Cooper-pair box. By applying a short voltage pulse via a gate electrode, we can control the coherent quantum state evolution: the pulse modifies the energies of the two charge states non-adiabatically, bringing them into resonance. The resulting state—a superposition of the two charge states—is detected by a tunnelling current through a probe junction. Our results demonstrate electrical coherent control of a qubit in a solid-state electronic device.
TI - Coherent control of macroscopic quantum states in a single-Cooper-pair box
JF - Nature
DO - 10.1038/19718
DA - 1999-04-29
UR - https://www.deepdyve.com/lp/springer-journals/coherent-control-of-macroscopic-quantum-states-in-a-single-cooper-pair-TJv1WcN8wn
SP - 786
EP - 788
VL - 398
IS - 6730
DP - DeepDyve
ER -