Detection of a Schroedinger's Cat State in an rf-SQUID
| dc.creator | Friedman, Jonathan R. | |
| dc.creator | Patel, Vijay | |
| dc.creator | Chen, W. | |
| dc.creator | Tolpygo, S. K. | |
| dc.creator | Lukens, J. E. | |
| dc.date | 2000-04-18 | |
| dc.date | 2000-04-19 | |
| dc.date.accessioned | 2026-07-07T02:37:24Z | |
| dc.date.available | 2026-07-07T02:37:24Z | |
| dc.description | We present experimental evidence for a coherent superposition of macroscopically distinct flux states in an rf-SQUID. When the external flux Phi_x applied to the SQUID is near 1/2 of a flux quantum Phi_0, the SQUID has two nearly degenerate configurations: the zero- and one-fluxoid states, corresponding to a few microamperes of current flowing clockwise or counterclockwise, respectively. The system is modeled as a particle in a double-well potential where each well represents a distinct fluxoid state (0 or 1) and the barrier between the wells can be controlled in situ. For low damping and a sufficiently high barrier, the system has a set of quantized energy levels localized in each well. The relative energies of these levels can be varied with Phi_x. External microwaves are used to pump the system from the well-localized ground state of one well into one of a pair of excited states nearer the top of the barrier. We spectroscopically map out the energy of these levels in the neighborhood of their degeneracy point by varying Phi_x as well as the barrier height. We find a splitting between the two states at this point, when both states are below the classical energy barrier, indicating that the system attains a coherent superposition of flux basis states that are macroscopically distinct in that their mean fluxes differ by more than 1/4 Phi_0 and their currents differ by several microamperes. | |
| dc.description | 3 RevTeX pages, 4 postscript figures, one in color. Submitted to Nature. Fig. 1 replaced (Postscript problem fixed) | |
| dc.identifier | https://arxiv.org/abs/cond-mat/0004293 | |
| dc.identifier | http://arxiv.org/abs/cond-mat/0004293 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/16277 | |
| dc.subject | Mesoscale and Nanoscale Physics | |
| dc.subject | Superconductivity | |
| dc.title | Detection of a Schroedinger's Cat State in an rf-SQUID | |
| dc.type | text |