Related papers: Systematic Improvements in Transmon Qubit Coherenc…
The fabrication of superconducting circuits requires multiple deposition, etch and cleaning steps, each possibly introducing material property changes and microscopic defects. In this work, we specifically investigate the process of argon…
The recent realization of millisecond-scale coherence with tantalum-on-silicon transmon qubits showed that depositing the Al/AlOx/Al Josephson junction in a high purity, ultrahigh vacuum environment was critical for achieving…
Superconducting qubits have arisen as a leading technology platform for quantum computing which is on the verge of revolutionizing the world's calculation capacities. Nonetheless, the fabrication of computationally reliable qubit circuits…
Decoherence of superconducting transmon qubits is purported to be consistent with surface loss from two-level systems on the substrate surface. Here, we present a study of surface loss in transmon devices, explicitly designed to have…
We report a superconducting artificial atom with an observed quantum coherence time of T2*=95us and energy relaxation time T1=70us. The system consists of a single Josephson junction transmon qubit embedded in an otherwise empty copper…
Hybrid superconductor/semiconductor devices play a crucial role in advancing quantum science and technology by merging the properties of superconductors and semiconductors. To operate these devices at high temperature, Niobium could…
Reducing materials and processing-induced decoherence is critical to the development of utility-scale quantum processors based on superconducting qubits. Here we report on the impact of two fluorine-based wet etches, which we use to treat…
One main limiting factor towards achieving high coherence times in superconducting circuits is two level system (TLS) losses. Mitigating such losses requires controlling the formation of native oxides at the metal-air interface. Here, we…
Transmon qubits fabricated with tantalum metal have been shown to possess energy relaxation times greater than 300 $\mu$s and, as such, present an attractive platform for high precision, correlated noise studies across multiple higher…
We report on the internal quality factor of a three-dimensional niobium quarter-wave coaxial cavity, with mid-temperature annealing, exhibiting $Q_{\rm int} \gtrsim 3\times10^9$ at the single-photon level below 20\,mK, which corresponds to…
For practical superconducting quantum processors, orders of magnitude improvement in coherence is required, motivating efforts to optimize hardware design and explore new materials. Among the latter, the coherence of superconducting…
Significant progress has been made in building large-scale superconducting quantum processors based on flip-chip technology. In this work, we use the flip-chip technology to realize a modified transmon qubit, donated as the "flipmon", whose…
Addressing and mitigating decoherence sources plays an essential role in the development of a scalable quantum computing system, which requires low gate errors to be consistently maintained throughout the circuit execution. While nuclear…
We demonstrate a sapphire machining process integrated with intermediate-scale quantum processors. The process allows through-substrate electrical connections, necessary for low-frequency mode-mitigation, as well as signal-routing, which…
We identify a major source of quantum decoherence in three-dimensional superconducting radio-frequency (SRF) resonators and two-dimensional transmon qubits composed of oxidized niobium: oxygen vacancies in the niobium pentoxide which drive…
This paper reports on a surface impedance measurement of a niobium titanium superconducting radio frequency (SRF) cavity in a magnetic field (up to $10\,{\rm T}$). A novel method is employed to decompose the surface resistance contributions…
Surface oxides are associated with two-level systems (TLSs) that degrade the performance of niobium-based superconducting quantum computing devices. To address this, we introduce a predictive framework for selecting metal capping layers…
One of the main limitations in state-of-the art solid-state quantum processors are qubit decoherence and relaxation due to noise in their local environment. For the field to advance towards full fault-tolerant quantum computing, a better…
Significant research has focused on low-power stochastic devices built from memristive materials. These devices foster neuromorphic approaches to computational efficiency enhancement in merged biomimetic and CMOS architectures due to their…
Quantum error correction will be an essential ingredient in realizing fault-tolerant quantum computing. However, most correction schemes rely on the assumption that errors are sufficiently uncorrelated in space and time. In superconducting…