Resonant effects in a SQUID qubit subjected to non adiabatic changes
arXiv:1310.5491 · doi:10.1103/PhysRevB.89.134506
Abstract
By 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 alternance 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 non-computational states.
6 pages and 6 figures. The paper, as it is, has been accepted for publication on PRB on March 2014
References in corpus (10)
- Beyond the Jaynes-Cummings model: circuit QED in the ultrastrong coupling regime
- Decoherence of flux qubits due to 1/f flux noise
- 1/f Flux Noise in Josephson Phase Qubits
- Temperature square dependence of the low frequency 1/f charge noise in the Josephson junction qubits
- Multimode circuit QED with hybrid metamaterial transmission lines
- Coherent oscillations in a superconducting tunable flux qubit manipulated without microwaves
- Superconducting Analogues of Quantum Optical Phenomena: Macroscopic Quantum Superpositions and Squeezing in a SQUID Ring
- Catastrophe observation in a Josephson junction system
- Tunable Flux Qubit manipulated by fast pulses: operating requirements, dissipation and decoherence
- state generation of three Josephson qubits in presence of bosonic baths