2007/03/31 by Keiji Saito, Martijn Wubs, Sigmund Kohler +4 · 2 citations
Computer Science · Engineering · Mathematics · Physics and Astronomy · #Adiabatic process #Charge qubit #Condensed matter physics #Coupling (piping) #Degenerate energy levels #Diabatic #Diagonal #Dissipative system #Flux qubit #Mathematics #Molecular Junctions and Nanostructures #Phase qubit #Phase transition #Physics #Quantum #Quantum Information and Cryptography #Quantum and electron transport phenomena #Quantum mechanics #Quantum phase transition #Quantum tunnelling #Qubit #Zener diode #cond-mat.mes-hall #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.75.214308
published as Phys. Rev. B 75, 214308 (2007) · 16 pages, 8 figures
openalex publication_date 2007/06/29 · arxiv created 2007/07/17 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We study Landau-Zener transitions in a qubit coupled to a bath at zero temperature. A general formula that is applicable to models with a nondegenerate ground state is derived. We calculate exact transition probabilities for a qubit coupled to either a bosonic or a spin bath. The nature of the baths and the qubit-bath coupling is reflected in the transition probabilities. For diagonal coupling, when the bath causes energy fluctuations of the diabatic qubit states but no transitions between them, the transition probability coincides with the standard Landau-Zener probability of an isolated qubit. This result is universal as it does not depend on the specific type of bath. For pure off-diagonal coupling, by contrast, the tunneling probability is sensitive to the coupling strength. We discuss the relevance of our results for experiments on molecular nanomagnets, in circuit QED, and for the fast-pulse readout of superconducting phase qubits.