応用物理学輪講 I
7月14日
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発表の10日前までに office[at]ap.t.u-tokyo.ac.jp 宛てに「氏名」「指導教員」「発表題目(英語)」「要旨(英語)」「発表言語(英語または日本語)」を送付して下さい。
発表日
2023年7月14日(金)16:50~18:50

Aグループ

座長
赤塚 俊輔
指導
教員名
石坂 香子 教授
発表者名 村田 拡輝
指導教員名 芦原 聡 教授
発表題目(英語) Optical Amplification of High Repetition Rate Mid-IR Ultrafast Pulses for High Harmonic Generation in Solids
要旨(英語) The evolution of high-power ultrafast lasers pioneered non-perturbative strong-field phenomenon. Recently, high harmonic generation (HHG), a representative strong-field phenomena, has been found to occur in solids as well as in gases. The solid-state HHG can be operated under the room condition, and is more flexible than gas-state HHG due to the choice of the material and the structure. Hence, the development of compact, easy-to-use XUV light sources is expected.
To generate higher harmonics without damaging a solid crystal, Mid-Infrared (MIR) pumps are more suitable than visible light pumps. However, the conventional method to obtain high power MIR pulses such as Ti:Sapphire-based system suffers low repetition rate because of parametric conversion.
The purpose of this study is to obtain sufficient pulse energy of high-repetition-rate MIR pulses for HHG in solids by the amplification of the output pulses from the MIR laser oscillator. In this presentation, the design of the amplifier and the result so far will be reported.
発表言語 日本語
発表者名 宮村 岳昂
指導教員名 中村 泰信 教授
発表題目(英語) Shaping microwave photons with frequency tunability using a fixed-frequency superconducting qubit
要旨(英語) A scalable quantum computer requires quantum communication between remote chips, which can be implemented using an itinerant microwave photon [1, 2]. For this, one needs to control the frequency and shape of the microwave photon. Here, we demonstrate a frequency-tunable generation of a shaped microwave photon without using a frequency-tunable superconducting qubit.
[1] P. Kurpier et al., Nature 558, 264 (2018). [2] M. Pechal et al., Phys. Rev. X 4, 041010 (2014).
発表言語 英語
発表者名 森石 奎吾
指導教員名 高橋 陽太郎 准教授
発表題目(英語) Observation of nonreciprocal second harmonic generation in Weyl semimetal PrAlGe without inversion and time reversal symmetry
要旨(英語) In recent years, a variety of new phenomena have been studied by combining condensed matter physics and the mathematical concepts of topology. Even in well-known phenomena such as anomalous Hall effect and second-order nonlinear optical effects, topology have played a major role. In particular, the enhancement of the effects of second harmonic generation (SHG) in Weyl semimetals has attracted a great deal of attention.

In this study, I have performed a detailed study of second harmonic generation in Weyl semimetal PrAlGe with both inversion and time reversal symmetry breaking, and observed magnetization-induced SHG. Furthermore, we demonstrated a new optical functionality of Weyl semimetals, namely the nonreciprocal response due to the interference of non-magnetic and magnetization-induced term.
発表言語 日本語

Bグループ

座長
穴井 啓太郎
指導
教員名
武田 俊太郎 教授
発表者名 宮本 樹
指導教員名 長谷川 達生 教授
発表題目(英語) Responsive dynamics and switching of ferroelastic domains in three-dimensional molecular ferroelectrics
要旨(英語) Ferroelectric molecular crystals are potential alternatives to currently used complex oxides, owing to the compatibility with light-weight, flexible, or printed electronics, as well as facile processing and sustainability. We are specifically focusing on plastic/ferroelectric crystals (PFeC) with exceptional ferroelectricity from three-dimensional order-disorder transition. In this presentation, our study on unique dynamics of ferroelectric/ferroelastic domains in PFeC thin films under in-plane electric fields, which is responsible for the polarization switching, will be introduced. The associated results of microscopic domain behaviors and macroscopic switching are essential for prospective applications of these materials.
発表言語 日本語
発表者名 矢島 康平
指導教員名 渡辺 悠樹 准教授
発表題目(英語) Measurement-induced localization
要旨(英語) Recently, attention has been paid to the interplay between unitary time evolution and measurements in various systems. A notable example of emergent dynamical effects is measurement-induced phase transition (MIPT), which has been intensively studied on quantum circuits. This phase transition is originated from competition between a disentangling effect of quantum measurement and an entangling effect of unitary circuits. In our research, we try to observe another measurement-induced dynamical effect which differs from the conventional one in a sense that we focus on a single-particle wave function instead of a many-body wave function. In our protocol, the probability and error in quantum position measurement of a particle is set as a tunable parameter. We expect that we can observe localization of a wave function by tuning the probability and the strength of the error in measurement, since a particle spreads over a space during unitary time evolution whereas it is localized by performing frequent and accurate measurements. We analyze the property of this localization comparing with that of Anderson localization. This new protocol may find a new type of quantum dynamical phenomenon.
発表言語 日本語
発表者名 山下 陸
指導教員名 香取 秀俊 教授
発表題目(英語) Development of portable Sr optical lattice clock
要旨(英語) There are many applications expected of optical lattice clock with 10^-18 fractional frequency uncertainty. For example, it can be a high-accuracy altimeter because a clock ticks faster under high gravitational potential energy according to general relativity. It has been already demonstrated that we carry out chronometric levelling at the level of centimeter height resolution by using transportable optical lattice clocks at 10^-18 uncertainty [1].

Now, we are developing more compact and robust clocks for social implementation of optical lattice clock or further applications of it.

In this presentation, I will explain the progress of the latest clock development, focusing on Hz-level spectroscopy using the small-sized optical lattice clock.

[1] Takamoto, M. et al. Test of general relativity by a pair of transportable optical lattice clocks. *Nat. Photon. *14, 411-415(2020).
発表言語 日本語
発表者名 佐藤 秀樹
指導教員名 志村 努 教授
発表題目(英語)
要旨(英語)
発表言語