Publications (16)
Experimentally revealing anomalously large dipoles in a quantum-circuit dielectric
Liuqi Yu, Shlomi Matityahu, Yaniv J. Rosen +5
Quantum two-level systems (TLSs) intrinsic to glasses induce decoherence in many modern quantum devices, such as superconducting qubits. Although the low-temperature physics of the…
Long-distance transmon coupler with CZ gate fidelity above
Fabian Marxer, Antti Vepsäläinen, Shan W. Jolin +36
Tunable coupling of superconducting qubits has been widely studied due to its importance for isolated gate operations in scalable quantum processor architectures. Here, we demonstr…
Hyperfine-phonon spin relaxation in a single-electron GaAs quantum dot
Leon C. Camenzind, Liuqi Yu, Peter Stano +4
Understanding and control of the spin relaxation time is among the key challenges for spin based qubits. A larger is generally favored, setting the fundamental upper li…
Static and Dynamic Signatures of Anisotropic Electronic Phase Separation in La2/3Ca1/3MnO3 Thin Films under Anisotropic Strain
Longqian Hu, Liuqi Yu, Peng Xiong +5
The electronic phase separation (EPS) of optimally doped La2/3Ca1/3MnO3 (LCMO) thin films under various degrees of anisotropic strain is investigated by static magnetotransport and…
A Superconducting Qubit-Resonator Quantum Processor with Effective All-to-All Connectivity
Michael Renger, Jeroen Verjauw, Nicola Wurz +62
In this work we introduce a superconducting quantum processor architecture that uses a transmission-line resonator to implement effective all-to-all connectivity between six transm…
Machine learning enables completely automatic tuning of a quantum device faster than human experts
H. Moon, D. T. Lennon, J. Kirkpatrick +10
Device variability is a bottleneck for the scalability of semiconductor quantum devices. Increasing device control comes at the cost of a large parameter space that has to be explo…
Spectroscopy of Quantum-Dot Orbitals with In-Plane Magnetic Fields
Leon C. Camenzind, Liuqi Yu, Peter Stano +4
We show that in-plane-magnetic-field assisted spectroscopy allows extraction of the in-plane orientation and full 3D shape of the quantum mechanical orbitals of a single electron G…
Orbital effects of a strong in-plane magnetic field on a gate-defined quantum dot
Peter Stano, Chen-Hsuan Hsu, Leon Camenzind +3
We theoretically investigate the orbital effects of an in-plane magnetic field on the spectrum of a quantum dot embedded in a two-dimensional electron gas (2DEG). We derive an effe…
Isotropic and Anisotropic g-factor Corrections in GaAs Quantum Dots
Leon C. Camenzind, Simon Svab, Peter Stano +5
We experimentally determine isotropic and anisotropic g-factor corrections in lateral GaAs single-electron quantum dots. We extract the Zeeman splitting by measuring the tunnel rat…
Robust Gapless Surface State against Surface Magnetic Impurities on (BiSb)Te Evidenced by In Situ Magnetotransport Measurements
Liuqi Yu, Longqian Hu, Jorge L. Barreda +5
Despite extensive experimental and theoretical efforts, the important issue of the effects of surface magnetic impurities on the topological surface state of a topological insulato…
Nonlinear Hall effect as a signature of electronic phase separation in the semimetallic ferromagnet EuB6
Xiaohang Zhang, Liuqi Yu, Stephan von Molnar +2
This work reports a study of the nonlinear Hall Effect (HE) in the semimetallic ferromagnet EuB6. A distinct switch in its Hall resistivity slope is observed in the paramagnetic ph…
Signatures of electronic phase separation in the Hall effect of anisotropically strained La0.67Ca0.33MnO3 films
Liuqi Yu, Lingfei Wang, Xiaohang Zhang +4
Systematic transport measurements have been performed on a series of La0.67Ca0.33MnO3 (LCMO) thin films with varying degrees of anisotropic strain. The strain is induced via epitax…
Bias-preserving and error-detectable entangling operations in a superconducting dual-rail system
Nitish Mehta, James D. Teoh, Taewan Noh +69
For useful quantum computation, error-corrected machines are required that can dramatically reduce the inevitable errors experienced by physical qubits. While significant progress…
Probing hundreds of individual quantum defects in polycrystalline and amorphous alumina
Chih-Chiao Hung, Liuqi Yu, Neda Foroozani +3
Quantum two-level systems (TLSs) are present in the materials of qubits and are considered defects because they limit qubit coherence. For superconducting qubits, the quintessentia…
Efficiently measuring a quantum device using machine learning
D. T. Lennon, H. Moon, L. C. Camenzind +6
Scalable quantum technologies will present challenges for characterizing and tuning quantum devices. This is a time-consuming activity, and as the size of quantum systems increases…
Detection of low-energy fluxons from engineered long Josephson junctions for efficient computing
Han Cai, Liuqi Yu, Waltraut Wustmann +2
Single-Flux Quantum (SFQ) digital logic is typically energy efficient and fast, and logic that uses ballistic and reversible principles provides a new platform to improve efficienc…