Quasiparticle Decoherence in d-wave Superconducting Qubits

Abstract

It is usually argued that the presence of gapless quasiparticle excitations at the nodes of the d-wave superconducting gap should strongly decohere the quantum states of a d-wave qubit, making quantum effects practically unobservable. Using a self-consistent linear response non-equilibrium quasiclassical formalism, we show that this is not necessarily true. We find quasiparticle conductance of a d-wave grain boundary junction to be strongly phase dependent. Midgap states as well as nodal quasiparticles contribute to the conductance and therefore decoherence. Quantum behavior is estimated to be detectable in a qubit containing a d-wave junction with appropriate parameters.

4 pages, 3 figures, final version to appear in PRL

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Cited by in corpus (15)

• Macroscopic quantum tunneling in a d-wave high-Tc superconductor
• Enhanced Macroscopic Quantum Tunneling in Bi${}_2$Sr${}_2$CaCu${}_2$O${}_{8+\delta }$ Intrinsic Josephson Junction Stacks
• Macroscopic Quantum Tunneling and Quasiparticle Dissipation in d-wave Superconductor Josephson Junctions
• Silent Phase Qubit Based on d-Wave Josephson Junctions
• Effect of zero energy bound states on macroscopic quantum tunneling in high-Tc superconductor junctions
• Switching Dynamics of Bi${}_2$Sr${}_2$CaCu${}_2$O${}_{8+\delta }$ Intrinsic Josephson junctions: Macroscopic Quantum Tunneling and Self-Heating Effect
• Theory of Macroscopic Quantum Tunneling in High-T_c c-Axis Josephson Junctions
• Macroscopic quantum tunneling and quasiparticle-tunneling blockade effect in s-wave/d-wave hybrid junctions
• Theory of Macroscopic Quantum Tunneling and Dissipation in High-Tc Josephson Junctions
• Decoherence of Phase Qubit using High-Tc Superconductor
• Theory of quantum transport in Josephson junctions with a ferromagnetic insulator
• Dissipative phase transition in two-dimensional d-wave Josephson junctions
• Density of states in d-wave superconductors of finite size
• Atomic scale 0-pi transition in a high-Tc superconductor/ferromagnetic-insulator/high-T superconductor Josephson junction
• Arrays of Josephson junctions between unconventional superconductors