3 papers
cond-mat.supr-con2008
Spectral densities of superconducting qubits with environmental resonances
Kaushik Mitra, C. J. Lobb, C. A. R. Sá de Melo
In this paper we derive the environmental spectral density for flux, phase and charge qubits when each of them is coupled to an environment with a resonance. From the spectral dens…
cond-mat.supr-con2007
Environmentally-Induced Rabi Oscillations and Decoherence in Phase Qubits
Kaushik Mitra, C. J. Lobb, C. A. R. Sá de Melo
We study decoherence effects in a dc SQUID phase qubit caused by an isolation circuit with a resonant frequency. The coupling between the SQUID phase qubit and its environment is m…
cond-mat.other2007
Vortices, antivortices and superfluid shells separating Mott-insulating regions
Kaushik Mitra, C. J. Williams, C. A. R. Sa de Melo
Atomic or molecular bosons in harmonically confined optical lattices exhibit a wedding cake structure consisting of insulating (Mott) shells. It is shown that superfluid regions em…