45 citations · 98 across the 12 of their papers we have counts for
12 papers
Engineered two-photon dissipative confinement of a Kerr-cat qubit using SISIS quantum circuit refrigerator
Shumpei Masuda, Tsuyoshi Yamamoto, Shuji Nakamura +2
Kerr-cat qubits realized in periodically driven superconducting nonlinear resonators are a promising platform for quantum information processing with biased noise. Pure dephasing i…
Ultralow-power coherent qubit control using AQFP logic at millikelvin temperatures
Hiroto Mukai, Akiyoshi Tomonaga, Rui Wang +5
Qubit controllers are essential for scaling superconducting quantum processors, but implementing them at the 10 mK stage of a dilution refrigerator remains challenging due to strin…
Efficient spectrum analysis for multi-junction superconducting circuit
A. Tomonaga, H. Mukai, K. Mizuno +1
The extraction of transition frequencies from a spectrum has conventionally relied on empirical methods, and particularly in complex systems, it is a time-consuming and cumbersome…
Residual--coupling suppression and fast two-qubit gate for Kerr-cat qubits based on level-degeneracy engineering
Takaaki Aoki, Akiyoshi Tomonaga, Kosuke Mizuno +1
Building large-scale quantum computers requires an interqubit-coupling scheme with a high on-off ratio to avoid unwanted crosstalk coming from residual coupling and to enable fast…
Probing instantaneous quantum circuit refrigeration in the quantum regime
Shuji Nakamura, Teruaki Yoshioka, Sergei Lemziakov +8
Recent advancements in circuit quantum electrodynamics have enabled precise manipulation and detection of the single energy quantum in quantum systems. A quantum circuit refrigerat…
Stabilization of Kerr-cat qubits with quantum circuit refrigerator
Shumpei Masuda, Shunsuke Kamimura, Tsuyoshi Yamamoto +2
A periodically-driven superconducting nonlinear resonator can implement a Kerr-cat qubit, which provides a promising route to a quantum computer with a long lifetime. However, the…
Spectral Properties of Two Superconducting Artificial Atoms Coupled to a Resonator in the Ultrastrong Coupling Regime
Akiyoshi Tomonaga, Roberto Stassi, Hiroto Mukai +3
We experimentally investigate a superconducting circuit composed of two flux qubits ultrastrongly coupled to a common LC resonator. Owing to the large anharmonicity of the flux qub…
Active Initialization Experiment of Superconducting Qubit Using Quantum-circuit Refrigerator
Teruaki Yoshioka, Hiroto Mukai, Akiyoshi Tomonaga +5
The initialization of superconducting qubits is one of the essential techniques for the realization of quantum computation. In previous research, initialization above 99\% fidelity…
Observation and manipulation of quantum interference in a superconducting Kerr parametric oscillator
Daisuke Iyama, Takahiko Kamiya, Shiori Fujii +9
Quantum tunneling is the phenomenon that makes superconducting circuits "quantum". Recently, there has been a renewed interest in using quantum tunneling in phase space of a Kerr p…
Ultrastrong tunable coupler between superconducting LC resonators
Takafumi Miyanaga, Akiyoshi Tomonaga, Hikaru Ito +2
We investigate the ultrastrong tunable coupler for coupling of superconducting resonators. Obtained coupling constant exceeds 1 GHz, and the wide range tunability is achieved both…
Quasiparticle tunneling and 1/f charge noise in ultrastrongly coupled superconducting qubit and resonator
Akiyoshi Tomonaga, Hiroto Mukai, Fumiki Yoshihara +1
We report an experimentally observed anomalous doubly split spectrum and its split-width fluctuation in an ultrastrongly coupled superconducting qubit and resonator. From an analys…
Superconducting Quantum Annealing Architecture with LC Resonators
Hiroto Mukai, Akiyoshi Tomonaga, Jaw-Shen Tsai
We propose a novel architecture for superconducting circuits to improve the efficiency of a quantum annealing system. To increase the capability of a circuit, it is desirable for a…