Probing Noise in Flux Qubits via Macroscopic Resonant Tunneling
arXiv:0712.0838 · doi:10.1103/PhysRevLett.101.117003
Abstract
Macroscopic resonant tunneling between the two lowest lying states of a bistable RF-SQUID is used to characterize noise in a flux qubit. Measurements of the incoherent decay rate as a function of flux bias revealed a Gaussian shaped profile that is not peaked at the resonance point, but is shifted to a bias at which the initial well is higher than the target well. The r.m.s. amplitude of the noise, which is proportional to the decoherence rate 1/T_2^*, was observed to be weakly dependent on temperature below 70 mK. Analysis of these results indicates that the dominant source of low frequency (1/f) flux noise in this device is a quantum mechanical environment in thermal equilibrium.
4 pages 4 figures
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- Hybrid quantum annealing for larger-than-QPU lattice-structured problems
- Experimental demonstration of perturbative anticrossing mitigation using non-uniform driver Hamiltonians
- Tunneling spectroscopy using a probe qubit
- Correlated flux noise and decoherence in two inductively coupled flux qubits
- Probing High Frequency Noise with Macroscopic Resonant Tunneling
- Quantum tunneling and level crossings in the squeeze-driven Kerr oscillator
- Observation of Co-tunneling in Pairs of Coupled Flux Qubits
- Nonequilibrium Spin Noise and Noise of Susceptibility
- NSQUID arrays as conveyers of quantum information
- Dissipative Landau-Zener tunneling in the crossover regime from weak to strong environment coupling
- Experimental Demonstrations of Native Implementation of Boolean Logic Hamiltonian in a Superconducting Quantum Annealer
- Probing flux and charge noise with macroscopic resonant tunneling
- Quantum adiabatic theorem for unbounded Hamiltonians with a cutoff and its application to superconducting circuits
- Noisy Demkov-Kunike model
- Flux-qubit and the law of angular momentum conservation
- A numerical study of the Bose-Einstein condensates in a double-well trap using finite differences
- Model validation and error attribution for a drifting qubit
- The Perturbed Ferromagnetic Chain: A Tuneable Test of Quantum Hardness in the Transverse-Field Ising Model