座長：奥村 駿、熊澤 正浩
座長： 北井 賢吾、越川 翔太
| 氏名： 小林
指導教員名： 古澤 明 教授
発表題目（英語）： A broadband dynamic squeezing gate by use of an FPGA
要旨（英語）： Quantum gates are classified into two groups, Gaussian gate and Non-Gaussian gate. All Gaussian gate are realized now. On the other hand, any non-Gaussian gate has never been realized yet. In order to realize an arbitrary quantum gate, Gaussian gate and at least one non-Gaussian gate are need. Therefore, we aim to realize a cubic phase gate, which is one of non-Gaussian gate.
In quantum optics, in order to realize quantum gates, feedforward process has been used. In order to realize a cubic phase gate, a nonlinear feedforward is needed. A dynamic squeezing gate was designed and realized by Miyata and others. A dynamic squeezing gate is a feedforward gate of a cubic phase gate. A dynamic squeezing gate is programmable and controlled by the control signal. In this research, in order to realize a cubic phase gate, we implemented a broadband dynamic squeezing gate by using a broadband and high-speed FPGA board.
| 氏名： 下起
指導教員名： 嶽山 正二郎 教授
発表題目（英語）： Ultra-high Magnetic Field and Physics of Graphite
要旨（英語）： Since Oersted found the magnetic field created by electric current, scientists have invented a lot of methods to generate high magnetic fields. While non-destructive magnet can generate magnetic field up to 100 T, destructive magnet can reach over 100 T. Graphite has been investigated by using non-destructive magnet and recently field-induced phase transitions were found.
In this presentation, I am going to explain the physical properties of graphite under high magnetic field and also describe my research plan above 100 T.
| 氏名： 笹川
指導教員名： 福谷 克之 教授
発表題目（英語）： Ortho-para conversion of molecular hydrogen promoted on solid surfaces
要旨（英語）： Molecular hydrogen occurs in two isomeric states, ortho H2 and para H2 with its two proton nuclear spins aligned parallel and antiparallel, respectively. Although interconversion between two isomers is negligibly slow, it is promoted on surfaces to approach thermal equilibrium. The dynamics of the interconversion has recently been investigated on well-defined surfaces, indicating that the conversion occurs not only on magnetic but also diamagnetic surfaces. Ortho-para conversion relates to a variety of fields including hydrogen liquefaction and astrophysics. To avoid boil-off losses that one caused by rotational-energy dissipation due to the nuclear spin conversion, ortho H2 needs to be converted to para H2 in advance of liquefaction using catalysts. Ortho-para conversion on interstellar media is expected to provide us with deeper understanding of astronomical phenomena. Furthermore, surface magnetism can be explored by distinction of ortho and para H2. Here, I will show the theory of ortho-para conversion on various surfaces and introduce the previous research and future application.
| 氏名： 秦
指導教員名： 岩 佐 義宏 教授
発表題目（英語）： Electrical characterization of Lead Telluride Colloidal Quantum Dots Assemblies
要旨（英語）： Colloidal quantum dots (CQDs) assemblies emerge as a new type of hybrid solid thin film that exploit the size-dependent quantum confinement properties of individual QDs: energy band gap variations and formation of discrete energy sub-bands. This material system is prospective especially for optoelectronics and thermoelectric devices. Nevertheless, it is urgent to clarify whether the quantum confinement properties are well-preserved in such a large scale assemblies. Furthermore, the large number of material variations, as well as size and shapes of the quantum dots may lead to different quantum confinement properties, such as the energy band gap and the formed discrete quantum level.
However, there are only few experiments to clarify the preservation of quantum confinement properties. So far, it is hindered by the fact that there are too many charge carrier traps due to the large surface area of the QDs that makes carrier modulation and doping difficult.
Here we demonstrate electrical characterization of PbTe CQDs assemblies using electric-double-layer transistor (EDLT). PbTe CQDs have low band gap and they are proper materials to observe quantum level, and EDLT can accumulate very large carrier density and it is expected to fill trap states of CQDS almost completely.
In this presentation, I will report the current states of my research.
| 氏名： 澤近
指導教員名： 田中 肇 教授
発表題目（英語）： Liquid-liquid transition in a molecular liquid
要旨（英語）： Contrary to the conventional wisdom that there is only one unique liquid state for any material, some evidences suggest that there can be more than two liquid states even for a single-component substance. The transition between these liquid states is called a “liquid-liquid phase transition (LLP)”. In the 1990s, there was a number of experimental indications suggestive of its existence in “monoatomic liquids” (e.g., C, P, Se, S) at high pressure and a high temperature. In 2004, our group found that the experimental evidence that LLP occurred in a “molecular liquid” triphenyl phosphite (TPP) at ambient pressure.
In recent years, our group has showed experimental evidence that above mentioned transition is truly LLP for TPP and several groups has reported that the common polyalcohol D-mannitol may occur LLP. A lot of research has been conducted up to this day.
In this presentation, as well as introducing an overview of the physics of soft condensed matter and the details of LLP, I mention the progress of my research.