# Hot Topic

## Visiting Berkeley

2019-05-09

Tsukasa Tada, the coordinator of iTHEMS, has visited SUURI-COOL Berkeley, last week. During his stay, Tada gave a seminar at the Berkeley Center for Theoretical Physics, which is one of the best group dedicated to particle physics and string theory. He also enjoyed the reunion with three iTHEMS members stationed at Berkeley, Takashi Okada, Jason Chang, and Masahiro Nozaki. All of them were having a great time at Berkeley. We strongly encourage iTHEMS members to visit SUURI-COOL Berkeley and take advantage of the prestigious environment of the University of California, Berkeley, and the Lawrence Berkeley National Laboratory.

Berkeley-iTHEMS Seminar by Dr. T.Tada

May 1 at 15:40 - 17:30, 2019

# Seminar Report

## Report of iTHEMS colloquium - Quantum computing: current status and prospects

2019-05-09

On April 25th, iTHEMS Colloquium featured Prof. Keisuke Fujii from Osaka University. Prof. Fujii has just moved to Osaka and started his laboratory for Quantum computing.

Started with quoting Richard Feynman and went on to summarize the history of quantum computing. Then he gave a pedagogical explanation of the principle of quantum computing and the overview of the subject.

Next, among over three hundred papers at Quantum Algorithm Zoo, he singled out Quantum Phase estimation as the most important Algorithm. Prof. Fujii explained the algorithm and told the audience that it has application to Prime factorization, Quantum Chemistry and Quantum simulation as well as Quantum linger system solver, which has relevance to AI.

He then gave the assessment of the current status of quantum computing and future prospect. The lecture was concluded by the exposition of Quantum-classical hybrid algorithm and its application to machine learning. Because of the exciting topic featured, the lecture attracted many keen audience.

# Research News

## Masaru Hongo and Tatsuhiro Misumi were highlighted in a recent article of RIKEN RESEARCH "A smaller spin system yields its phase diagram"

2019-05-08

By employing a clever approximation, three theoretical physicists at RIKEN (Masaru Hongo and Tatsuhiro Misumi of the iTHEMS and Yuya Tanizaki of the RIKEN BNL Research Center) have calculated the phase diagram for an extension of a system proposed over 30 years ago. In addition to advancing the theory of condensed matter physics, this finding could have practical implications for systems made up of particles with the quantum property of spin.

This research highlighted in a recent article of RIKEN RESEARCH.

# Research News

## Review on synthetic dimensions published in Nature Reviews Physics

2019-05-08

Nature Reviews Physics is a new journal, just launched this year, focusing on publishing reviews in the area of physics. Dr. Tomoki Ozawa (iTHEMS Senior Research Scientist) together with Dr. Hannah M. Price (University of Birmingham, UK) wrote a review for Nature Reviews Physics on “synthetic dimension,” which is a recently emerging method for simulating high dimensional models using low dimensional platforms making use of non-spatial degrees of freedom as effective dimensions. The review summarizes the current status of the research of synthetic dimensions with a focus on atomic, molecular, and optical physics, where the method is most actively studied. A figure from the review is also adapted for the cover of the May 2019 issue of Nature Reviews Physics.

Journal Reference: T. Ozawa and H. M. Price, “Topological quantum matter in synthetic dimensions,” Nature Reviews Physics 1, 349–357 (2019).

# Upcoming Events

## Lecture

### Introduction to Quantum Computation

May 13 - 15, 2019

Dr. Shunji Matsuura (Fundamental Researcher, Quantum Simulation division, 1QBit)

The schedule of the lectures on "Quantum Computation" by Dr. Shunji Matsuura (1QBit) is as follows.

May 13 (Mon)

[Lecture 1] 10:00-11:30, [Lecture 2] 14:00-15:30

May 14 (Tues)

[Lecture 3] 10:00-11:30, [Lecture 4] 14:00-15:30

May 15 (Wed)

[Lecture 5] 10:00-11:30, [Lecture 6] 14:00-15:30

Venue: Nishina Hall, 2F Nishina Building, RIKEN

Event Official Language: English

## Special Lecture

### How did the Universe Begin? -Inflation Theory & Road to the Proof-

May 21 at 15:00 - 16:30, 2019

Dr. Katsuhiko Sato (Professor Emeritus, The University of Tokyo / Director, Research Center for Science Systems, Japan Society for the Promotion of Science)

Venue: Okochi Hall, 1F Laser Science Laboratory, RIKEN

Broadcast: R511, Computational Science Research Building, R-CCS, Kobe Campus, RIKEN / SUURI-COOL (Kyoto), #204-205, 2F Maskawa Building for Education and Research, North Campus, Kyoto University / SUURI-COOL (Sendai), #303, 3F AIMR Main Building, Advanced Institute for Materials Research (AIMR), Tohoku University

Event Official Language: Japanese

## School

### g-RIPS Sendai 2019

June 17 - August 9, 2019

GRIPS (Graduate-level Research in Industrial Projects for Students)-Sendai program was held last summer (June 18 - Aug. 10, 2018) with the support of iTHEMS as well as other institutions and companies. Two industrial projects were launched under the suggestion of TOYOTA and NEC, and two teams composed of US and Japanese students have worked intensively to find solutions of these problems. See for the details of the GRIPS program and the summary of activities at GRIPS-Sendai 2018.

This year, GRIPS-Sendai program will be held from June 17 through Aug. 9, 2019 with a larger scale under the support of iTHEMS. Stay tuned for further information.

Event Official Language: English

## Workshop

### Workshop on Sine-square deformation and related topics 2019

July 11 at 10:00 - 18:00, 2019

Sine-Square Deformation (SSD) is a newly found boundary condition that involves the spatial modulation of the coupling constant of quantum systems.

Since its discovery, it has received broad attention in the context of various research field. This workshop aims at offering the opportunities for the researchers interested in SSD to convene and exchange ideas on the subject.

Venue: #435-437, Main Research Building, RIKEN

Event Official Language: Japanese

# Upcoming Visitor

May 13 - 15, 2019 ## Dr. Shunji MatsuuraFundamental Researcher, Quantum Simulation division, 1QBit Research fields: Quantum Computing Visiting Place: Main Research Building |

# Person of the Week

## Self-introduction: Kenta Sato

2019-04-26

Hello, I am Kenta Sato. My major is mathematics, in particular algebraic geometry. In algebraic geometry, we study algebraic varieties, which are defined as the zero sets of polynomial equations. When you hear polynomials, you may imagine polynomials whose coefficients are integers, rational numbers, or complex numbers. But, it sometimes important to consider polynomials whose coefficients are in some other field, for example a field with positive characteristic.

I have been studying polynomials, rings and algebraic varieties over a field with positive characteristic. In particular, I am interested in F-singularities and globally F-regular varieties, which are defined in terms of positive characteristic methods. I also hope to find some application of positive characteristic methods to problems in mathematics and other areas.

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