6 papers
Quantum Constrained Hamiltonian Descent
Yoshihiko Abe, Ryo Nagai
We propose Quantum Constrained Hamiltonian Descent (QCHD), a continuous-time quantum framework for optimization under smooth equality constraints. The unconstrained counterpart, Qu…
First measurement of the low-momentum negative-muon beam for the muon-to-electron conversion experiment at J-PARC
The COMET Collaboration, K. Oishi, R. Abramishvili +183
The COMET Phase- experiment, the initial beam-operation stage of the COMET muon-to-electron conversion programme at J-PARC, took place in 2023 and marked the first beam operatio…
Thermalization in a repeated-interaction model with memory effects
Kanji Nishii, Ryo Nagai, Yoshihiko Abe
We study how memory affects the thermalization of a qubit in a repeated-interaction model. In our model, a memory qubit interacts repeatedly with the system, while both qubits unde…
Surface-Code Thresholds and Qubit Footprints in Shuttling-Based Spin-Qubit Railways
Arun John Moncy, Reza Dastbasteh, Josu Etxezarreta Martinez +5
We present a fault-tolerant mapping of rotated surface codes onto a silicon spin-qubit railway architecture, utilizing electron shuttling to resolve the wiring fan-out…
Quantum Riemannian Hamiltonian Descent
Yoshihiko Abe, Ryo Nagai
We propose Quantum Riemannian Hamiltonian Descent (QRHD), a quantum algorithm for continuous optimization on Riemannian manifolds that extends Quantum Hamiltonian Descent (QHD) by…
Digital-Controlled Method of Conveyor-Belt Spin Shuttling in Silicon for Large-Scale Quantum Computation
Ryo Nagai, Takashi Takemoto, Yusuke Wachi +1
We propose a digital-controlled conveyor-belt shuttling method for silicon-based quantum processors, addressing the scalability challenges of conventional analog sinusoidal impleme…