Protected Hybrid Superconducting Qubit in an Array of Gate-Tunable Josephson Interferometers
Constantin Schrade, Charles M. Marcus, András Gyenis
DOI 10.1103/PRXQuantum.3.030303 · PRX Quantum
Active bibliographic source — not scientific approval
Bibliographic access preserves source history; it does not approve extracted materials or validate reported claims. Review warnings on each occurrence separately.
Abstract
We propose a protected qubit based on a modular array of superconducting islands connected by semiconductor Josephson interferometers. The individual interferometers realize effective cos2ϕ elements that exchange “pairs of Cooper pairs” between the superconducting islands when gate tuned into balance and frustrated by a half-flux quantum. If a large capacitor shunts the ends of the array, the circuit forms a protected qubit because its degenerate ground states are robust to offset-charge and magnetic field fluctuations for a sizable window around zero offset charge and half-flux quantum. This protection window broadens upon increasing the number of interferometers if the individual elements are balanced. We use an effective spin model to describe the system and show that a quantum phase transition sets the critical flux value at which protection is destroyed.
Similar papers
Parity-Protected Superconductor-Semiconductor Qubit
similarity 0.94T. W. Larsen et al.
Source status unknown — claims are unverified
A Parity-Protected Superconductor-Semiconductor Qubit
similarity 0.91T. W. Larsen et al. · 2020 · arXiv:2004.03975
Source status unknown — claims are unverified
Decoherence-protected spin-photon quantum gates in a hybrid semiconductor-superconductor circuit
similarity 0.91Li Wang et al.
Source status unknown — claims are unverified
Sample and hold strategy for quantum measurements of Josephson charge qubits
similarity 0.89V. Schöllmann et al.
Source status unknown — claims are unverified
Hybrid ferromagnetic transmon qubit: Circuit design, feasibility, and detection protocols for magnetic fluctuations
similarity 0.89Halima Giovanna Ahmad et al.
Source status unknown — claims are unverified
Semiconductor-Nanowire-Based Superconducting Qubit
similarity 0.89T. W. Larsen et al.
Source status unknown — claims are unverified