| Masao Hirokawa | Last modified dateļ¼2023.11.27 |
Professor /
Department of I&E Visionaries /
Faculty of Information Science and Electrical Engineering
Presentations
| 1. | Masao Hirokawa, SUSY breaking and a radiative mass enhancement in quantum Rabi model with A^2-term, Rabi model and Spin-Boson Model, 2023.01, [URL]. |
| 2. | Masao Hirokawa, Can We Make the Noise Filtering Theory for NISQ Computer?, 14th Superconducting SFQ VLSI Workshop & 3rd Workshop on Quantum Classical Cryogenic Devices, CIrcuits, and Systems, 2021.09, [URL]. |
| 3. | Yasusi Kanada, Masao Hirokawa, Stochastic problem solving by local computation based on self-organization paradigm, Proceedings of the 27th Hawaii International Conference on System Sciences (HICSS-27). Part 4 (of 5), 1994, We are developing a new problem-solving methodology based on a self-organization paradigm. To realize our future goal of self-organizing computational systems, we have to study computation based on local information and its emergent behavior, which are considered essential in self-organizing systems. This paper presents a stochastic (or nondeterministic) problem solving method using local operations and local evaluation functions. Several constraint satisfaction problems are solved and approximate solutions of several optimization problem are found by this method in polynomial order time in average. Major features of this method are as follows. Problems can be solved using one or a few simple production rules and evaluation functions, both of which work locally, i.e., on a small number of objects. Local maxima of the sum of evaluation function values can sometimes be avoided. Limit cycles of execution can also be avoided. There are two methods for changing the locality of rules. The efficiency of searches and the possibility of falling into local maxima can be controlled by changing the locality.. |
| 4. | Masao Hirokawa, Securing Data by Noise-Disturbance in the Light of Quantum Sensing Device, International Symposium on Mathematics, Quantum Theory, and Cryptography (MQC 2019), 2019.09, We are interested in a mathematical method and a technology for its implementation for securing data on physical layer of our developing quantum-sensing device because the device detects and handles some ultimate personal information. I talk about the joint research with my student, Tomohiro Fujii. In the joint research, we use a noise-disturbance instead of using cryptograph. . |
| 5. | Masao Hirokawa, Approximated Eigenstates of Generalized Quantum Rabi Model with A^2-Term in Deep-Strong Coupling Regime, Strongly Coupled Light-Matter Interactions 2018: Models and Applications, 2018.07, We give a procedure to approximate eigenstates of the generalized quantum Rabi Hamiltonian both without and with a quadratic interaction for the deep-strong coupling regime. Based on it, in the case without the quadratic interaction, we show that whether each approximated bare eigenstate forms a Schroedinger-cat-like entangled state or a separate state depends on whether the bias energy in the atom Hamiltonian is zero or non-zero, and then, the effect of the atom is ignored in the approximation. On the other hand, in the case with the quadratic interaction, we consider its renormalization, and show that all the approximated physical eigenstates form individual Schroedinger-cat-like entangled states for every bias energy, and this fact comes from the effect of the atom.. |
| 6. | Masahiko Ichimura, Masao Hirokawa, Topological Superconductors in Ferromagnetic Nanowires with Domain Wall, LLC and the IEEE Magnetics Society, 2019.01, We report on the numerical results for the edge effect in the finite length of the ferromagnetic nanowires with a domain wall. The Majorana bound states (MBS) emerges at the edge of the topological superconductor (TSC) region for sufficiently large value of the effective strong spin-orbit interaction (SOI). From the local spin density, we obtain the result that the MBS with exponential decay forms a pair at the both edges of the TSC region and the decay length become smaller with larger effective SOI. . |
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