Volume 47

iTHEMS Weekly News Letter

Hot Topic

Congratulations on new positions, farewell message from Program Director of iTHEMS

2019-03-27

This is the last volume of iTHEMS NewsLetter in FY2018. It is our great pleasure that iTHEMS has been so active during this fiscal year. Some of the members will leave iTHEMS.

Keisuke Fujii (JSPS Research fellow (DC2)).
Shun Furusawa (specially appointed assistant prof., Tokyo Univ. of Science)
Masaru Hongo (specially appointed assistant prof., Keio Univ.)
Motoko Kato (specially appointed assistant prof., Ehime Univ.)
Masashi Tachikawa (associate prof., Kyoto Univ.),
Ade Irma Suriajaya (specially appointed assistant prof., Kyushu Univ.).

We congratulate them for new positions and look forward to their further success !

Award

Dr. Iritani receives the Best English Presentation Award

2019-03-26

Ryosuke Iritani (iTHEMS, Research Scientist) received "the Best English Presentation Award" on March 16, 2019 for his English presentation, When parasites are selected to kill the young, at the 66th Annual Meeting of the Ecological Society of Japan. Congratulations !

Hot Topic

Article of Dr. Ade Irma Suriajaya on RIKEN Research “Making the most of zeros”

2019-03-25

Article of Dr. Ade Irma Suriajaya has been posted on RIKEN Research. Please check out the interview on her research life !

Upcoming Events

Seminar

Tensor Berry connections and their topological invariants

April 2 (Tue) at 14:00 - 15:00, 2019

Giandomenico Palumbo (Researcher, Université Libre de Bruxelles, Belgium)

The Berry connection plays a central role in our description of the geometric phase and topological phenomena. In condensed matter, it describes the parallel transport of Bloch states and acts as an effective "electromagnetic" vector potential defined in momentum space. Inspired by developments in high-energy physics, where higher-form Kalb-Ramond gauge fields were introduced, I hereby explore the existence of "tensor Berry connections" in quantum matter. My approach consists in a general construction of effective gauge fields, which I ultimately relate to the components of Bloch states. I apply this formalism to various models of topological matter, and I investigate the topological invariants that result from generalized Berry connections. I introduce the 2D Zak phase of a tensor Berry connection, which I then relate to the more conventional first Chern number; I also reinterpret the winding number characterizing 3D topological insulators to a Dixmier-Douady invariant, which is associated with the curvature of a tensor connection. Besides, my approach identifies the Berry connection of tensor monopoles, which are found in 4D Weyl-type systems in ultracold atoms.

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

Event Official Language: English

Seminar

ABBL-iTHEMS Joint Astro Seminar

The Origin of the X-ray Clumpy Ejecta in Type Ia Supernova Remnants

April 3 (Wed) at 14:00 - 15:00, 2019

Toshiki Sato (Special Postdoctoral Researcher, High Energy Astrophysics Laboratory, RIKEN Cluster for Pioneering Research (CPR))

X-ray-emitting clumpy structures are generally observed in young Type Ia supernova remnants although the origin is still obscure. There are two candidates for explaining the formation of clumps; initial clumpiness in ejecta at the explosion (i.e., clumpy ejecta model) or hydrodynamic instabilities made from smooth ejecta profile (i.e., smooth ejecta model). This information should reflect the initial ejecta structure of SNe Ia, so it is important for understanding the Type Ia explosion itself. Our preliminary investigations into constraining the structure of SN Ia remnants using Fourier and wavelet-transform analyses did not turn out to be sufficiently powerful at discriminating the two hydro models and the observed Tycho image from each other. This led us to investigate an approach that would be more sensitive to patterns in the distribution of clumps and holes in the images, such as the "genus statistic.”
In this study, for the first time, the genus statistics have been applied to a famous type Ia remnant, Tycho (SN 1572) to understand the formation of the clumps by comparing with hydrodynamical models (Sato et al. 2019, arXiv: 1903.00764). We found the genus curve from Tycho's supernova remnant strongly indicates a skewed non-Gaussian distribution of the ejecta clumps, which is similar to that of a hydrodynamical model for the clumpy ejecta model. In contrast, a hydrodynamical model for the smooth ejecta model has a genus curve that is similar to that of a random Gaussian distribution. Thus, our results support the initial clumpiness in the Type Ia ejecta is more reasonable for the origin of the clumps and demonstrate usefulness of the genus statistics for this field. In addition, we will also discuss the origin of “Fe-rich” ejecta clumps in Type Ia SNRs in this seminar.

Venue: #433, Main Research Building, RIKEN

Event Official Language: English

Math Lecture

Introduction to Public-Key Cryptography

Introduction to Public-Key Cryptography (10th)

April 9 (Tue) at 13:30 - 15:30, 2019

Eren Mehmet Kıral (Visiting Scientist, iTHEMS / Visiting Scientist (JSPS Research Fellow), Faculty of Science and Technology, Sophia University)

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

Event Official Language: English

Colloquium

The 8th MACS Colloquium thumbnail

MACS ColloquiumSupported by iTHEMSSUURI-COOL (Kyoto)

The 8th MACS Colloquium

April 12 (Fri) at 15:00 - 17:30, 2019

Hayato Chiba (Professor, Advanced Institute for Materials Research (AIMR), Tohoku University)

15:00- Teatime
15:15- Talk by Prof. Hayato Chiba
16:45- MACS Student Conference FY2019

The 8th MACS colloquium is supported by iTHEMS. It will be broadcasted to Wako, but if you can join the colloquium physically in Kyoto, that would be better. iTHEMS provides good confectionary at Kyoto!

Venue: Lecture room #401, Graduate School of Science Building No 6, Kyoto University

Broadcast: #235, 2F, Main Research Building, RIKEN

Event Official Language: Japanese

Workshop

International Molecule-type Workshop "Frontiers in Lattice QCD and related topics"

April 15 (Mon) - 26 (Fri), 2019

International Molecule-type Workshop "Frontiers in Lattice QCD and related topics" will be held in Yukawa Institute for Theoretical Physics (YITP) on April 15 - 26, 2019 under the support of iTHEMS and YITP.

Lattice quantum chromodynamics (QCD) is a systematic method to investigate strong interaction of hadrons with numerical simulations. In this workshop, frontiers of lattice QCD will be discussed under relaxed atmosphere in Kyoto.

Organizers: Sinya Aoki (YITP), Yasumichi Aoki (RIKEN, CCS), Hidenori Fukaya (Osaka U.), Shoji Hashimoto (KEK), Tetsuo Hatsuda (RIKEN, iTHEMS), Takumi Doi (RIKEN, Nishina Center), Atsushi Watanabe (YITP)

Venue: Yukawa Institute for Theoretical Physics, Kyoto University

Event Official Language: English

Colloquium

iTHEMS Colloquium

Quantum computing: current status and prospects

April 25 (Thu) at 15:00 - 16:30, 2019

Keisuke Fujii (Professor, Graduate School of Engineering Science, Osaka University)

Supported by extensive experimental efforts for realization of quantum computing devices, quantum computers of a hundred qubits are now within reach in the near future. This level of a quantum computer is not enough for fully fledged fault-tolerant quantum computing, but is still expected to have computational advantage against classical computers.
Such a noisy intermediate scale quantum computing (NISQ) device is thought to be a testbed for proof-of-principle experiments of quantum algorithms and verification of quantum physics in the limit of extremely high complexity.
In this talk, I will provide a general introduction to quantum computing starting from how and for what quantum computers work. Then I will provide an overview of the current status and prospects of the field of quantum computing. As the final part, I will also talk about our own activities on quantum-classical hybrid algorithm, which is a kind of quantum algorithms specifically designed for the NISQ devices.

Venue: Suzuki Umetaro Hall, 1F Bioscience Building, 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

Seminar

Berkeley-iTHEMS Seminar

Three quantizations of conformal field theory

May 1 (Wed) at 15:40 - 17:30, 2019

Tsukasa Tada (Coordinator, iTHEMS / Vice Chief Scientist, Quantum Hadron Physics Laboratory, RIKEN Nishina Center for Accelerator-Based Science (RNC))

Needless to say, conformal field theory is elemental in the study of string theory, statistical quantum systems, and various quantum field theories.
Two-dimensional conformal field theory is usually quantized by the so-called radial quantization. However, this is not the only way. As a matter of fact, there are two other distinctive choices for the time foliation, or equivalently, the Hamiltonian. One of these choices yields the continuous Virasoro algebra, while the other choice leads to the Virasoro algebra on a torus. The former case corresponds to the recently found (and perhaps less known) phenomenon, sine-square deformation. The latter yields the well-known entanglement entropy. I will present a comprehensive treatment of these three quantizations and discuss its physical implications.

Venue: Old LeConte Hall 402, UC Berkeley

Event Official Language: English

School

AIMR Main Building venue photo

g-RIPS Sendai 2019

June 17 (Mon) - August 9 (Fri), 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.

Venue: 4F Research Space, AIMR Main Building, Advanced Institute for Materials Research (AIMR), Tohoku University

Event Official Language: English

Upcoming Visitor

March 30 (Sat) - April 8 (Mon), 2019

Giandomenico Palumbo

Researcher, Université Libre de Bruxelles, Belgium

Visiting Place: Main Research Building

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