arXiv subjects

Leo Matsuoka

Publications and source records attributed to Leo Matsuoka.

6 recordsLinked to original sources

arXiv2026

Artifact side peaks in saturated absorption spectroscopy caused by inappropriate lock-in amplification

Saturated absorption spectroscopy is a powerful technique that provides valuable information about gas-phase atomic targets, including not only the precise positions of transitions but also the effects of velocity-changing collisions, which manifest as changes in the shape of the peaks. However, using a lock-in amplifier inappropriately can generate artifact side peaks, potentially leading to a misinterpretation of results. To investigate the emergence of these artifacts, we conducted numerical calculations based on the basic Lambert-Beer's law. Our model reproduced the artifact side peaks and revealed that these artifacts become more significant as the transmittance of the probe laser decreases.

physics.atom-ph↗

arXiv2024

A mathematical framework for maze solving using quantum walks

We provide a mathematical framework for identifying the shortest path in a maze using a Grover walk, which becomes non-unitary by introducing absorbing holes. In this study, we define the maze as a network with vertices connected by unweighted edges. Our analysis of the stationary state of the Grover walk on finite graphs, where we strategically place absorbing holes and self-loops on specific vertices, demonstrates that this approach can effectively solve mazes. By setting arbitrary start and goal vertices in the underlying graph, we obtain the following long-time results: (i) in tree structures, the probability amplitude is concentrated exclusively along the shortest path between start and goal; (ii) in ladder-like structures with additional paths, the probability amplitude is maximized near the shortest path.

quant-ph↗

arXiv2022

Design for implementation of discrete-time quantum walk with circulant matrix on graph by optical polarizing elements

In this paper, we introduce a quantum walk whose local scattering at each vertex is denoted by a unitary circulant matrix; namely the circulant quantum walk. We also introduce another quantum walk induced by the circulant quantum walk; namely the optical quantum walk, whose underlying graph is a $2$-regular directed graph and obtained by blowing up the original graph in some way. We propose a design of an optical circuit which implements the stationary state of the optical quantum walk. We show that if the induced optical quantum walk does not have $+1$ eigenvalue, then the stationary state of the optical quantum walk gives that of the original circulant quantum walk. From this result, we give a useful condition for the setting of the circulant quantum walks which can be implemented by this optical circuit.

quant-ph↗

arXiv2017

Resonant-tunneling in discrete-time quantum walk

We show that discrete-time quantum walks on the line, $\mathbb{Z}$, behave as "the quantum tunneling". In particular, quantum walkers can tunnel through a double-well with the transmission probability $1$ under a mild condition. This is a property of quantum walks which cannot be seen on classical random walks, and is different from both linear spreadings and localizations.

quant-ph↗

arXiv2015

Unified parameter for localization in isotope-selective rotational excitation of diatomic molecules using a train of optical pulses

We obtained a simple theoretical unified parameter for the characterization of rotational population propagation of diatomic molecules in a periodic train of resonant optical pulses. The parameter comprises the peak intensity and interval between the pulses, and the level energies of the initial and final rotational states of the molecule. Using the unified parameter, we can predict the upper and lower boundaries of probability localization on the rotational level network, including the effect of centrifugal distortion. The unified parameter was tentatively derived from an analytical expression obtained by performing rotating-wave approximation and spectral decomposition of the time-dependent Schrödinger equation under an assumption of time-order invariance. The validity of the parameter was confirmed by comparison with numerical simulations for isotope-selective rotational excitation of KCl molecules.

quant-ph↗

arXiv2011

Numerical Study on Quantum Walks Implemented on the Cascade Rotational Transitions in a Diatomic Molecule

We propose an implementation scheme for the continuous-time quantum walk using a diatomic molecule and an optical frequency comb. We show an analogy between the quantum walk and the cascade rotational transitions induced by the optical frequency comb whose frequency peaks are tuned to the pure rotational transitions in the molecule. The strategy to compensate for the centrifugal distortion of the real molecule is also demonstrated.

quant-ph↗