Quantum localized modes in capacitively coupled Josephson junctions

Abstract

We consider the quantum dynamics of excitations in a system of two capacitively coupled Josephson junctions. Quantum breather states are found in the middle of the energy spectrum of the confined nonescaping states of the system. They are characterized by a strong excitation of one junction. These states perform slow tunneling motion from one junction to the other, while keeping their coherent nature. The tunneling time sensitively depends on the initial excitation energy. By using an external bias as a control parameter, the tunneling time can be varied with respect to the escape time and the experimentally limited coherence time. Thus one can control the flow of quantum excitations between the two junctions.

5 pages, 3 figures. Improved version, title was slightly changed. Accepted in Europhysics Letters (http://www.iop.org/EJ/journal/EPL)

References in corpus (9)

• Discrete Breathers
• State tomography of capacitively shunted phase qubits with high fidelity
• Tunable coupling of superconducting qubits
• Quantum Lattice Solitons
• Quantum Breathers in a Nonlinear Lattice
• Spectroscopy of capacitively coupled Josephson-junction qubits
• Fidelity and quantum chaos in the mesoscopic device for the Josephson flux qubit
• Chaotic dynamics in superconducting nanocircuits
• Quantum dynamics of localized excitations in a symmetric trimer molecule

Cited by in corpus (3)

• Quantum breathers in capacitively coupled Josephson junctions: Correlations, number conservation, and entanglement
• Array of Josephson junctions with a non-sinusoidal current-phase relation as a model of the resistive transition of unconventional superconductors
• Resonant invisibility with finite range interacting fermions