# CMSI International Workshop 2014: Tensor Network Algorithms in Materials Science

When |
Oct 20, 2014 12:00 AM
to
Oct 22, 2014 12:00 AM |
---|---|

Where | RIKEN AICS |

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## Aims and scope:

The tensor network algorithm is one of the most efficient and promising numerical methods for expressing a quantum state of many-body systems in condensed-matter physics and quantum chemistry. The tensor scheme has achieved a great progress recently with the help of the matrix decomposition technique in computational science, the concept of entanglement in quantum information theory, and the advanced formulation of tensor train in mathematics. The objective of this workshop is to offer a forum where concerned researchers can exchange information on the latest results and newly established methodologies, and discuss the computational technique and future directions of the interdisciplinary study between the computational chemistry, physics, mathematics, and the computer science.

Topics:

- Tensor network based algorithms: MPS, DMRG, PEPS, MERA, and more.
- Numerical techniques: tensor product, matrix diagonalization, higher-order SVD, etc.
- Application to strongly correlated systems in quantum chemistry and physics.
- Relation with quantum information, entanglement, etc.

## Date:

October 20 Monday - 22 Wednesday, 2014

This workshop was finished. Thank you for your participation.

## Venue:

RIKEN Advanced Institute for Computational Science 6F auditorium

7-1-26, Port Island South, Kobe, 650-0047, Japan

[access information]

## Invited Speakers:

Philippe Corboz (Institute for Theoretical Physics, University of Amsterdam, Netherlands)

Hiroyuki Ishigami (Graduate School of Informatics, Kyoto University, Japan)

Naoki Nakatani (Catalysis Research Center, Hokkaido University, Japan)

Tsuyoshi Okubo (The Institute for Solid State Physics, The University of Tokyo, Japan)

Kouichi Okunishi (Department of Physics, Niigata University, Japan)

Robert Peters (RIKEN Advanced Science Institute, Japan)

Didier Poilblanc (Laboratoire de Physique Theorique, CNRS-UMR5152, Universite de Toulouse III, France)

Hana Saito (NIC Research Group Elementary Particles at DESY, Germany)

Norbert Schuch (Institute for Quantum Information RWTH Aachen University, Germany)

Edward F. Valeev (Virginia Polytechnic Institute and State University, USA)

Tao Xiang (Institute of Physics Chinese Academy of Science, China)

Takeshi Yanai (National Institutes of Natural Sciences Institute for Molecular Science, Japan)

## Program:

**Day-1: Oct. 20th (Mon)**

- 9:00 - Registration
- 10:00 – Opening

- 10:10 – Edward F. Valeev (Department of Chemistry, Virginia Tech, USA) [60+30min]
*TiledArray: Scalable C++ Toolkit for Block-Sparse Tensor Computing"*

- 11:40 – Lunch at FOCUS
- 13:00 – Kouichi Okunishi (Department of Physics, Niigata University, Japan) [30+15min]
*"Fixed point structure of the tensor renormalization group in 1+1 dimension”*

- 13:45 - Hana Saito (NIC Research Group Elementary Particles at DESY, Zeuthen, Germany) [30+15min]
*"Hamiltonian approach to Lattice Gauge Theory: Temperature dependence of the chiral condensate in the Schwinger model with Matrix Product State"*

- 14:30 – Coffee break and discussion time
- 15:30 - Tao Xiang (Institute of Physics Chinese Academy of Science, China) [60+30min]
*"Tensor renormalization of quantum lattice models"*

Special Seminar sponsored by Research Center for Nano-Micro Structure Science and Engineering, University of Hyogo

- 16:50 - Synge Todo (Department of Physics, University of Tokyo) [20min]
*"MateriApps: a Portal Site for Materials Science Simulation"*

- 17:10 –
**Poster Session** - 18:30 – Banquet at AICS lounge (attending charge is 4,000 yen)

**Day-2: Oct. 21st (Tue)**

- 9:30 – Didier Poilblanc (Laboratoire de Physique Theorique, CNRS-UMR5152, Universite de Toulouse III, France) [60+30min]
*"Simulating correlated electronic and spin systems with PEPS"*

- 11:00 – K computer tour & group photo
- 12:00 – Lunch at FOCUS
- 13:30 - Robert Peters (AICS Advanced Science Institution, Japan) [30+15min]
*“Quantum impurity models within the Density Matrix Renormalization Group”*

- 14:15 - Hiroyuki Ishigami (Graduate School of Informatics, Kyoto University, Japan) [30+15min]
*“Development of Parallel SVD Solver for Large-scale Sparse Matrix”*

- 15:00 - Coffee break and discussion time
- 16:00 - Takeshi Yanai (National Institutes of Natural Sciences Institute for Molecular Science, Japan) [60+30min]
*“Ab initio quantum chemistry with density matrix renormalization group”*

- 18:00 - Dinner at Kobe downtown

**Day-3: Oct. 22nd (Wed)**

- 9:30 - Norbert Schuch (Institute for Quantum Information RWTH Aachen University, Germany) [60+30min]
*“Identifying quantum order from the transfer operator”*

- 11:00 - Tsuyoshi Okubo (The Institute for Solid State Physics, The University of Tokyo, Japan) [30+15min] "Ground state calculation of the generalized Kitaev-Heisenberg model using PEPS tensor network method"

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- 11:45 - Lunch at FOCUS
- 13:30 - Naoki Nakatani (Catalysis Research Center, Hokkaido University, Japan) [30+15min]
*"Tensor Network Perspectives in Quantum Chemistry"* - 14:15 - Philippe Corboz (Institute for Theoretical Physics, University of Amsterdam, Netherlands) [60+30min]
*"Recent progress in simulating strongly correlated systems with iPEPS"*

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- 15:45 - Closing

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## Poster Session (Oct. 20th 17:10-18:30):

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- Shinji Hamada (Toyohashi University of Technology)

"DMET (Density Matrix Embedding Theory) calculation applied to the Hubbard model on the honeycomb lattice" - Kenji Harada (Kyoto University)

"Tensor network calculation on large scale parallel computer" - Takahiro Ohgoe (The University of Tokyo)

"Multi-variable variational Monte Carlo method for electron-phonon coupled systems" - Akira SaiToh (Toyohashi University of Technology)

"Numerical estimation of quantum errors using multiprecision MPS" - Tatsuya Sakashita (ISSP)

"Exact diagonalization package using integrated interface for parallel eigensolvers" - Hideo Sekino (Toyohashi University of Technology)

"An application of Density Matrix Embedding Theory on 6 membered ring systems" - Shigetoshi Sota (RIKEN AICS)

"Massively parallel DMRG method and its application" - Takafumi Suzuki (University of Hyogo)

"Dynamical properties of the Heisenberg-Kitaev model on the honeycomb lattice" - Kazuhiko Tanimoto (Kyoto University)

"Topological phase of SU(N) Heisenberg chain with iTEBD algorithm" - Koichi Yanagisawa (The University of Tokyo)
*"Corner Transfer Matrix Renormalization for S=1/2 J1-J2 Heisenberg Model on Square Lattice"* - Hui-Hai Zhao (The University of Tokyo)
*"PEPS on finite periodic lattice"*

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## Organizers:

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Hidemaro Suwa (Univ. Tokyo, Chair)

Naoki Nakatani (Hokkaido Univ.)

Synge Todo (Univ. Tokyo)

Naoki Kawashima (ISSP)

Kazuo Kitaura (Kobe University)

Tatsuya Sakashita (ISSP)

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## Contact:

Hidemaro Suwa, Ph.D., Assistant Professor

Department of Physics, The University of Tokyo

7-3-1 Hongo Bunkyo Tokyo 113-0033 Japan

Tel: (+81)-3-5841-4194

E-mail: suwamaro@phys.s.u-tokyo.ac.jp

## Cosponsor:

Research Center for Nano-Micro Structure Science and Engineering, University of Hyogo