Abstract: Landau-Zener transition (LZT) is ubiquitous in quantum systems with time-dependent Hamiltonians. LZ physics has broad applications in atomic and molecular physics, quantum optics, condensed matter physics, chemical physics, and quantum information science. For instance, LZT has been used as tunable "beam splitters" of wave functions to generate entangled multipartite states. Its potential for robust manipulation of coherent quantum states has attracted much attention. We demonstrate, via experiment and numerical simulation that under conditions often found in superconducting qubits LZ probability PLZ could deviate from that described by the asymptotic LZ formula. Under proper conditions, in contrast to the smooth exponential dependence of PLZ on the Landau-Zener speed v predicted by the LZ formula PLZ oscillates as a function of v and the range diabatic energy sweep which we call the anomalous LZ oscillation (ALZO). We show that if not taking into consideration ALZO could lead to significant for single- and two-qubit quantum gates based on adiabatic passage. 

Date&Time: November 28, 2013 (Thursday), 10:00-11:00 a.m.
Location: 606 Conference Room, No.3 Heqing Road, Haidian District