Anno2014
AutoriChiarello F.; Spilla S.; Castellano M.G.; Cosmelli C.; Messina A.; Migliore R.; Napoli A.; Torrioli G.
AbstractBy quickly modifying the shape of the effective potential of a double SQUID flux qubit from a single-well to a double-well condition, we experimentally observe an anomalous behavior, namely, an alternation of resonance peaks, in the probability to find the qubit in a given flux state. The occurrence of Landau-Zener transitions as well as resonant tunneling between degenerate levels in the two wells may be invoked to partially justify the experimental results. A quantum simulation of the time evolution of the system indeed suggests that the observed anomalous behavior can be imputable to quantum coherence effects. The interplay among all these mechanisms has a practical implication for quantum computing purposes, giving a direct measurement of the limits on the sweeping rates possible for a correct manipulation of the qubit state by means of fast flux pulses, avoiding transitions to noncomputational states. © 2014 American Physical Society.
RivistaPhysical Review. B, Condensed Matter And Materials Physics
ISSN1098-0121
Impact factor0
Volume89
Pagina inizio134506
Pagina fine
Autori IBFRosanna MIGLIORE
Linee di Ricerca IBFMD.P01.004.001
Sedi IBFIBF.PA