Related papers: Absence of Charge Offset Drift in a Transmon Qubit
Superconducting qubits are among the most promising platforms for realizing practical quantum computers. One requirement to create a quantum processor is nonlinearity, which in superconducting circuits is typically achieved by sandwiching a…
A Josephson junction may be driven through a transition where the superconducting condensate favors an odd over an even number of electrons. At this switch in the ground-state fermion parity, an Andreev bound state crosses through the Fermi…
We present a hybrid semiconductor-based superconducting qubit device which remains coherent at magnetic fields up to 1 T. The qubit transition frequency exhibits periodic oscillations with magnetic field, consistent with interference…
We introduce a novel superconducting qubit architecture utilizing parallel arrays of Josephson junctions. This design offers a substantialy improved relative anharmonicity, typically within the range of $|\alpha_r| \approx 0.1 - 0.3$, while…
Based on a network graph analysis of the underlying circuit, a quantum theory of arbitrary superconducting charge qubits is derived. Describing the dissipative elements of the circuit with a Caldeira-Leggett model, we calculate the…
Topological superconductors are appealing building blocks for robust and reliable quantum information processing. Most platforms for engineering topological superconductivity rely on a combination of superconductors, materials with…
The simultaneous suppression of charge fluctuations and offsets is crucial for preserving quantum coherence in devices exploiting large quantum fluctuations of the superconducting phase. This requires an environment with both extremely low…
We solve the problem of an interacting quantum dot embedded in a Josephson junction between two superconductors with finite charging energy described by the transmon (Cooper pair box) Hamiltonian. The approach is based on the flat-band…
We propose and theoretically investigate spin superconducting qubits. Spin superconducting qubit consists of a single spin confined in a Josephson junction. We show that owing to spin-orbit interaction, superconducting difference across the…
We report on long-term measurements of a highly coherent, non-tunable superconducting transmon qubit, revealing low-frequency burst noise in coherence times and qubit transition frequency. We achieve this through a simultaneous measurement…
We study a model Hamiltonian for superconductivity in underdamped Josephson junction arrays in the presence of an offset voltage between the array and the substrate. We develop an approximate zero-temperature (T = 0) phase diagram as a…
A quantum computer that can be constructed based on a superconducting nanocircuits has previously been proposed. We examine the effect of background charge fluctuations on a coupled Josephson charge qubit system used in such a computer. In…
Superconducting protected qubits aim to achieve sufficiently low error rates so as to allow realization of error-corrected, utility-scale quantum computers. A recent proposal encodes a protected qubit in the quasicharge degree of freedom of…
Superconducting circuits for quantum information processing are often described theoretically in terms of a discrete charge, or equivalently, a compact phase/flux, at each node in the circuit. Here we revisit the consequences of lifting…
In thin superconducting wires, phase-slip by thermal activation near the critical temperature is a well-known effect. It has recently become clear that phase-slip by quantum tunnelling through the energy barrier can also have a significant…
We study the effects of external offset charges on the phase diagram of Josephson junction arrays. Using the path integral approach, we provide a pedagogical derivation of the equation for the phase boundary line between the insulating and…
We evaluate the quasiparticle contribution to the frequency shift and relaxation rates of a transmon with the Josephson junctions connecting superconductors that have unequal energy gaps. The gap difference substantially affects the…
The interplay of superconductivity, magnetic fields, and spin-orbit interaction lies at the heart of topological superconductivity. Remarkably, the recent experimental discovery of $\varphi_{0}$ Josephson junctions by Szombati et al., Nat.…
Schemes aimed at transferring individual electrons in semiconductor devices and detecting possible transfer errors have increasing importance for metrological applications. We study the coupling of a superconducting Josephson-junction-based…
We investigate inelastic microwave photon scattering by a transmon qubit embedded in a high-impedance circuit. The transmon undergoes a charge-localization (Schmid) transition upon the impedance reaching the critical value. Due to the…