Volume 69

iTHEMS Weekly News Letter

Seminar Report

QCoIn Seminar given by Dr. Hirotaka Irie thumbnail

QCoIn Seminar given by Dr. Hirotaka Irie

2019-09-12

On Sep. 2 and 3, Dr. Hirotaka Irie (DENSO Corporation / iTHEMS visiting scientist; see his self-introduction in this volume of NewsLetter) gave a series of comprehensive lectures on "Quantum Annealing" which is a quantum computational scheme for hard optimization problems. This was held as a part of the iTHEMS QCoIn WG activity.

In the first day, he started the lecture by explaining the fundamental notions of quantum computation and quantum annealing, followed by the basic usage of quantum annealer.
In the second day, he discussed the notion of computational complexity in detail, and then showed various examples of the real-world applications of quantum annealer.
The lectures were given only by using white-board with detailed explanation of basic equations, which stimulated lots of questions from the audience. Discussions continued during the break and after the lectures.

Seminar Report

Lecture by Dr. Yuya Nakagawa from QunaSys

2019-09-10

An Academic-Industrial Innovation Lecture was delivered by Dr. Yuya Nakagawa from QunaSys on September 4th. QuanSys is a venture company specializes in quantum computing and Dr. Nakagawa joined QunaSys shortly after having earned his Ph. D.
In the first part, Dr. Nakagawa gave a concise overview of quantum computing. The second part of the lecture consisted of more detailed explanation including the result from QuanSys itself and the application to Quantum Chemistry.
The lecture attracted audience not only from RIKEN but also outside RIKEN, especially notable companies. The last part of the lecture turned out to be filled with a lot of questions from the keen audiences, and candid comments were exchanged. We felt that the lecture is really serving as a hub that connects people from academics and industry.

Outlook for Industrial Applications of Quantum Computers image

Seminar Report

Summary of the lecture of Introduction to quantum many-body system

2019-09-10

A lecture on “Introduction to quantum many-body system “ by Prof. Hosho Katsura was held from September 5 to 6 at RIKEN. In particular, we studied basic concepts of many-body systems on lattices and how to investigate their properties in analytical and numerical ways. In the first part of the lecture, non-interacting Fermi and Bose systems on lattices were focused and we learned how to calculate energy bands. Such systems included Kitaev chain and Su-Schrieffer-Heeger model for one-dimensional fermions as well as free bosons describing low-energy properties of quantum magnets. In the second part, we studied spin systems such as Affleck-Kennedy-Lieb-Tasaki model from the perspective of frustration-free systems and the concept of matrix product states.
The attendees were scientists from various backgrounds; physicists specializing in condensed-matter physics, atomic physics, nuclear physics, and particle physics as well as mathematicians. This lecture was filled with fruitful discussion and instructive to attendees who are not professional in lattice systems.

Upcoming Events

Seminar

iTHEMS Biology Seminar

September 13 (Fri) at 15:00 - 17:20, 2019

Hiroyuki Kubota (Professor, Medical Institute of Bioregulation, Kyushu University)
Yasufumi Uezu (Researcher, Sensory And Motor Research Group, NTT Communication Science Laboratories)

Timetable
15:00-16:00 Hiroyuki Kubota (Kyushu Univ.)
16:00-16:20 Break
16:20-17:20 Yasufumi Uezu (NTT)

Time: 15:00-16:00
Speaker: Hiroyuki Kubota (Kyushu Univ.)
Title: Regulation of insulin action by temporal patterns of insulin

Abstract: Cells respond to various extracellular stimuli through a limited number of signaling pathways. One strategy to process such stimuli is to code the information into the temporal patterns of molecules. Almost all hormones exhibit distinct temporal patterns and the importance of their patterns has been reported. However, the mechanisms of how hormones regulate downstream molecules depending on their temporal patterns remain unknown. We focused on insulin which plays crucial roles on glucose homeostasis and shows several temporal patterns in vivo. In this study, we show how the Insulin signaling pathway processes the information encoded into the temporal patterns of blood insulin using a cultured cell line and mice. We found that insulin patterns selectively regulate the insulin-AKT pathway, metabolites, and mRNAs. Mathematical modeling revealed the mechanisms via differences in network structures and from sensitivity and time constants. Given that almost all hormones exhibit distinct temporal patterns, temporal coding may be a general principle of system homeostasis by hormones.

Time: 16:20-17:20
Speaker: Yasufumi Uezu (NTT)
Title: Source-filter interaction brings various representation in speech and singing voice

Abstract: Speech plays a very important role in human communication. The source-filter interaction, a model that takes into account the actual speech production process, assumes that the sound source generation mechanism and the vocal-tract filter are not independent, but affect each other physiologically and acoustically. It is known that the source-filter interaction brings about non-linearity of speech and singing, such as singing voice with a loud volume and wide pitch range like an opera singer, or voice register transition where the vocal suppression and/or the voice pitch jump occurs. I would like to introduce my researches targeting non-linear vocalization phenomena due to the source-filter interaction and results of measuring and analyzing the time waveform of speech sound and vocal-fold vibrations through measurement experiments.

Venue: #424-426, Main Research Building, RIKEN

Event Official Language: Japanese

Seminar

ABBL-iTHEMS Joint Astro Seminar

Angular power spectrum analysis on current and future high-energy neutrino data

September 18 (Wed) at 14:00 - 15:00, 2019

Ariane Dekker (Faculty of Science, University of Amsterdam, Netherlands)

The astrophysical neutrino events that have been measured in the last couple of years show an isotropic distribution on the sky. To constrain the contribution of source populations to the observed neutrino sky, we consider isotropic and anisotropic components of the diffuse neutrino data. We simulate through-going muon neutrino events by applying statistical distributions for the fluxes of extra-galactic sources and investigate the sensitivities of current (IceCube) and future (IceCube-Gen2 and KM3NeT)
experiments. I will show that the angular power spectrum is a powerful probe to assess the angular characteristics of neutrino data and demonstrate that we are already constraining rare and bright sources with current IceCube data.
In addition, I will investigate the decay and annihilation of very heavy dark matter as a potential neutrino source suggested by the excess in HESE data. We apply our angular power spectrum analysis to HESE data for different channels, allowing us to interpret the observed neutrino sky and perform a sensitivity forecast.

Venue: #160, 1F, Main Research Building, RIKEN

Event Official Language: English

Colloquium

iTHEMS Colloquium

Topological phases of matter and operator algebras

October 4 (Fri) at 15:30 - 17:00, 2019

Yasuyuki Kawahigashi (Senior Visiting Scientist, iTHEMS / Professor, Graduate School of Mathematical Sciences, The University of Tokyo)

Topological phases of matter are hot topics in recent physics and related to a wide range of mathematical fields. I will talk about their aspects related to operator algebras. Our emphasis will be on theory of tensor categories which describe interactions of anyons. This theory plays an important role in topological quantum computations.
In theory of operator algebras, Jones initiated theory of subfactors and discovered the Jones polynomial, a new topological invariant for knots as an application. We apply this theory to mathematical studies of anyons.

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: English

Workshop

Workshop on Virtual Reality[Session 1]

October 7 (Mon) at 13:00 - 16:00, 2019

Gilles Ferrand and Don Warren will run a workshop on using virtual reality (VR) for data visualization and research. Anyone from any RIKEN campus, and any field of study, is welcome. We want to build a cross-disciplinary group of people with a shared interest in VR, and to apply this tool to a broad range of data types and topics.

Please check the workshop website for up-to-date information !

Venue: Seminar Room #132, 1F Main Research Building, RIKEN

Event Official Language: English

Lecture

RIKEN Open Campus in Kobe thumbnail
Integrated Innovation Building (IIB) venue photo

RIKEN Open Campus in Kobe

November 9 (Sat) at 10:00 - 16:30, 2019

Takumi Doi (Senior Research Scientist, iTHEMS / Senior Research Scientist, Quantum Hadron Physics Laboratory, RIKEN Nishina Center for Accelerator-Based Science (RNC))

RIKEN Open Campus in Kobe will be held on Nov.9, 2019.
Dr. Emiko Hiyama (Kyushu Univ.) and Dr. Takumi Doi (Nishina Center / iTHEMS) will give lectures on computational nuclear and particle physics at Kobe IIB building where SUURI-COOL Kobe is located. Please inform the news to anybody who are interested in visiting RIKEN Kobe.

Venue: Integrated Innovation Building (IIB), Kobe Campus, RIKEN

Event Official Language: Japanese

Upcoming Visitor

September 14 (Sat) - 30 (Mon), 2019

Bruno Kahn

Directeur de recherche, Institut de Mathématiques de Jussieu-Paris Rive Gauche (IMJ-PRG), France

Visiting Place: #233, 2F, Main Research Building

Person of the Week

Hirotaka Irie thumbnail

Self-introduction: Hirotaka Irie

2019-09-12

I am Hirotaka Irie, a research scientist in quantum computing team of DENSO Corporation. From this summer of 2019, I also became a visiting scientist here at RIKEN iTHEMS. I received my Ph.D. in Physics (string theory) at Kyoto University in 2008, and worked as postdoc in KEK, National Taiwan University, National Center for Theoretical Physics (NCTS, Taiwan), and Yukawa Institute for Theoretical Physics (Kyoto University), where my research focused on non-perturbative aspects of string theory and mathematical physics. Now I joined DENSO Corporation, working toward real-world applications of quantum mechanical computing machines with combining aspects of mathematical physics and string theory. In fact, recent industrial studies also require highly sophisticated physical and mathematical researches. Here, I hope to discuss and collaborate with people in iTHEMS to jointly achieve new technological breakthrough which changes our daily life and society.

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