aqora

Analysis of Rabi Oscillations of a Josephson Phase Qubit

S. K. Dutta, Huizhong Xu, Frederick W. Strauch +9 more

Bulletin of the American Physical SocietyMar 17, 20060 citations

Distinguishing quantum from classical Rabi oscillations in a phase qubit

Sergey N Shevchenko, A. N. Omelyanchouk, Alexandre M. Zagoskin +2 more

Dec 12, 20071 citation

Strong Field Effects in Rabi Oscillations of the dc SQUID Phase Qubit

S. K. Dutta, Tauno Palomaki, Rupert Lewis +7 more

Bulletin of the American Physical SocietyMar 6, 20070 citations

Temperature Dependence of Coherent Oscillations in Josephson Phase Qubits

Jürgen Lisenfeld, Alexander V. Lukashenko, M. Ansmann +2 more

We experimentally investigate the temperature dependence of Rabi oscillations and Ramsey fringes in superconducting phase qubits. In a wide range of temperatures, we find that both the decay time and the amplitude of these coherent oscillations remain nearly unaffected by thermal fluctuations. In the two-level limit, coherent qubit response rapidly vanishes as soon as the energy of thermal fluctuations k(B)T becomes larger than the energy level spacing variant Planck's over h omega of the qubit. In contrast, a sample of much shorter coherence times displayed semiclassical oscillations very similar to Rabi oscillation, but showing a qualitatively different temperature dependence. Our observations shed new light on the origin of decoherence in superconducting qubits. The experimental data suggest that, without degrading already achieved coherence times, phase qubits can be operated at temperatures much higher than those reported till now.We experimentally investigate the temperature dependence of Rabi oscillations and Ramsey fringes in superconducting phase qubits. In a wide range of temperatures, we find that both the decay time and the amplitude of these coherent oscillations remain nearly unaffected by thermal fluctuations. In the two-level limit, coherent qubit response rapidly vanishes as soon as the energy of thermal fluctuations k(B)T becomes larger than the energy level spacing variant Planck's over h omega of the qubit. In contrast, a sample of much shorter coherence times displayed semiclassical oscillations very similar to Rabi oscillation, but showing a qualitatively different temperature dependence. Our observations shed new light on the origin of decoherence in superconducting qubits. The experimental data suggest that, without degrading already achieved coherence times, phase qubits can be operated at temperatures much higher than those reported till now.

arXiv:0705.0095Physical Review LettersOct 26, 200756 citations

Method for direct observation of coherent quantum oscillations in a superconducting phase qubit

Ya. S. Greenberg, A. Izmalkov, M. Grajcar +3 more

Time-domain observations of coherent oscillations between quantum states in mesoscopic superconducting systems have so far been restricted to restoring the time-dependent probability distribution from the readout statistics. We propose a method for direct observation of Rabi oscillations in a phase qubit. The external source, typically in GHz range, induces transitions between the qubit levels. The resulting Rabi oscillations of supercurrent in the qubit loop induce the voltage oscillations across the coil of a high quality resonant tank circuit, inductively coupled to the phase qubit. It is the presence of these voltage oscillations in the detected signal which reveals the existence of Rabi oscillations in the qubit. A detailed calculation for zero and nonzero temperatures are made for the case of persistent current qubit. According to the estimates for decoherence and relaxation times, the effect can be detected using conventional rf circuitry, with Rabi frequency in the MHz range.Time-domain observations of coherent oscillations between quantum states in mesoscopic superconducting systems have so far been restricted to restoring the time-dependent probability distribution from the readout statistics. We propose a method for direct observation of Rabi oscillations in a phase qubit. The external source, typically in GHz range, induces transitions between the qubit levels. The resulting Rabi oscillations of supercurrent in the qubit loop induce the voltage oscillations across the coil of a high quality resonant tank circuit, inductively coupled to the phase qubit. It is the presence of these voltage oscillations in the detected signal which reveals the existence of Rabi oscillations in the qubit. A detailed calculation for zero and nonzero temperatures are made for the case of persistent current qubit. According to the estimates for decoherence and relaxation times, the effect can be detected using conventional rf circuitry, with Rabi frequency in the MHz range.

arXiv:cond-mat/0208143Physical review. B, Condensed matterDec 31, 200225 citations

Bath-induced persistent Rabi oscillations in a qubit

Jesper Ilves

Mar 12, 20190 citations

Temperature Dependence of Rabi Oscillations in Phase Qubits

Related papers

Temperature Dependence of Rabi Oscillations in Phase Qubits

Related papers