セミナー(2015.6.8)：Dr Panagiota PAPAKONSTANTINOU (IBS, RISP)

2015年6月3日 | 新着情報

韓国のiBSからPapakonstantinou氏が来られて以下のセミナーを行います。場所は自B214です。

Date/Time: June 8 (Mon), 13:45 pm-
Place: B214 (Institute of Natural Sciences, Univ. of Tsukuba)
Lecturer:  Panagiota PAPAKONSTANTINOU (Institute for Basic Science, Rare Isotope Science Project)
Title: Beyond the mean-field picture, with realistic nuclear interactions
Abstract:
In the past decades, energy-density functional methods have advanced greatly the field of nuclear structure. They have allowed a microscopic and unified description of many properties in medium-mass and heavy nuclei, from masses and sizes to giant resonances, as well as nuclear matter. Known issues include the poorly constrained time-odd terms and the concept of non-linear density dependencies. Fitting the free parameters on the mean-field level means, moreover, that double counting of unknown effects is inevitable in beyond-mean-field applications. In this talk I will present an effort to describe nuclear properties, starting from microscopic NN(N) Hamiltonians, which allows for systematic and controlled extensions of mean-field theory, and can thus be applied in heavy nuclei. The Hamiltonians are first softened via unitary transformations. They can describe nuclear ground states within perturbation theory. They are then applied in linear response theory, namely the random phase approximation and its extensions, to study giant resonances and other vibrational modes. This line of work bridges strictly ab initio methods, restricted to very low energies and light nuclei, and more phenomenological, traditional approaches. It exploits nsights from both and could help them advance in tandem.

セミナー(2015.5.22)：Dr Javier Menendez (東大理)

2015年5月15日 | 新着情報

東京大学に学振・外国人特別研究員・Javier Menendez氏のセミナーが5月22日(金) に予定されています。場所・時間等は、セミナーページをご覧ください。

Lecturer: Javier Menendez (Univ. of Tokyo)
Title: From nuclear structure to double-beta decay
Abstract:
First I will cover the main achievements, and point to future work, in nuclear structure shell model calculations of medium-mass nuclei based on nuclear forces predicted by chiral effective field theory. These include very successful description of masses and spectroscopy of oxygen, calcium isotopes as well as ‘sd-shell’ nuclei. Secondly I will discuss neutrinoless double-beta decay, a key process to access neutrino properties given that the nuclear matrix elements of the process are known accurately. I will present state-of-the-art shell-model neutrinoless double-beta decay calculations, and a comparison to other approaches such as based on mean-field, which is essential to improve our understanding of the nuclear matrix elements.

セミナー(2015.5.18)：Drs Rozzi and Pittalis (Istituto Nanoscienze)

2015年5月13日 | 新着情報

イタリアCNRのIstituto Nanoscienzeから、Carlo Andrea Rozzi氏とStefano Pittalis氏が研究室を訪問し、5/18(月) にセミナーをする予定です。場所と時間は通常と異なりますのでご注意ください。

(1)
Title: Ultrafast dynamics in light-harvesting and photovoltaics: a theoretical and experimental investigation
Speaker: Carlo Andrea Rozzi (CNR – Istituto Nanoscienze)
Place: Workshop room, Center for Computational Sciences
Time: May 18, 11:00-12:00
Abstract:
It is known that the primary steps of photoinduced energy and charge transfer occur on extremely fast time scales in many natural and man-made compounds that perform conversion of sunlight into chemical or electrical energy. These processes have traditionally been interpreted in terms of the incoherent kinetics of optical excitations and of charge hopping, but recently signatures of quantum coherence were observed in energy transfer in photosynthetic bacteria and algae [1,2]. We have studied the early steps of photoinduced charge separation in reference systems for artificial photosynthesis and photovoltaics by combining Time-dependent Density Functional Theory simulations of the quantum dynamics and high time resolution femtosecond spectroscopy. Our results show that the coherent coupling between electronic and nuclear degrees of freedom is of key importance for charge delocalization and transfer in both of covalently and non-covalently bonded systems [3,4]. We have exploited the results of our research to design, synthesize and characterize a novel molecular scaffold for photovoltaic applications [5].
[1] Engel, G. S. et al. Nature 446, 782-786 (2007).
[2] Collini, E. et al. Nature 463, 644-647 (2010).
[3] Rozzi, C. A., Falke S. et al., Nat. Comm. 4, 1602 (2013)
[4] Falke S., Rozzi, C. A. et al., Science, 344, 1001 (2014)
[5] Pittalis S., et al., Adv. Func. Mat. (2014)
(2)
Title: A roundtrip journey from spin-entanglement in atoms and molecules
to density functional theory
Speaker: Stefano Pittalis (CNR – Istituto Nanoscienze)
Place: Workshop room, Center for Computational Sciences
Time: 13:30-14:30
Abstract:
I will present an investigation on spin entanglement in many-electron systems within the framework of density functional theory [1]. In particular, I will show that, the entanglement length — which is extracted from the spatial dependence of the local concurrence — is a sensitive indicator of atomic shells, and reveals the character, covalent or metallic, of chemical bonds. These findings shed light on the remarkable success of modern density functionals, which tacitly employ the entanglement length as a variable, and open the way to further research on entanglement-based functionals.
[1] S. Pittalis, F. Troiani, C. A. Rozzi, G. Vignale, Phys. Rev. B 91, 075109 (2015)

ビジター（2015.6.22~8.16）：Dr Anatoli Afanasjev氏（ミシシッピ州立大学）

2015年5月1日 | 新着情報

ミシシッピ州立大学教授 Anatoli Afanasjev氏が6月22日より2ヶ月間、日本学術振興会外国人招へい研究者（短期）として筑波大学原子核理論研究室に滞在される予定です。

新メンバー：鷲山さん、齊藤さん、八百板さん。

2015年4月1日 | 新着情報

我々の研究グループに、理化学研究所から鷲山公平さんが研究員として着任し、新たにメンバーとして加わりました。柏葉さんは修士課程M1に進学。また、物理学類4年生の齊藤さん、八百板さんが新たに研究室配属となりました。

関澤さん博士(理学)、五嶌さん修士(理学)、数理物質科学研究科長賞（関澤さん）。

2015年3月25日 | 新着情報

関澤さんが博士(理学)、五嶌さんが修士(理学)を取得し、関澤さんの学位論文が数理物質科学研究科長賞を受賞しました。

数理物質科学研究科長賞を受賞した関澤さん(D3)。

第9回日本物理学会若手奨励賞（江幡氏）。

2015年3月21日 | 新着情報

原子核理論研究室出身の江幡修一郎氏(北大)が、大学院在学中の論文で第9回日本物理学会若手奨励賞を受賞しました。

ジョージア工科大学John Wood氏による特別講義。

2015年3月18日 | 新着情報

ジョージア工科大学名誉教授John Wood氏による特別講義(2015.3.16-18)を開催しました。

講義スライド（Lecture1, Lecture2, Lecture3)

Lecture by Wood

2015.3.18講義終了後に撮影。

第11回RIBF討論会(2015.3.2)を筑波大にて開催。

2015年3月3日 | 新着情報

2015年3月2日(月)に、第11回RIBF討論会

「重イオン反応と多核子移行」 (Heavy-ion reaction and multi-nucleon transfer)

を筑波大・総合研究B棟110にて開催しました。詳細はこちらへ。

Advances and perspectives in computational nuclear physics (2014.10.5-7)

2014年10月1日 | 新着情報

The meeting is held at Hilton Waokoloa Village in October 5-7, 2014. It is focused on latest theoretical and technical advances in computational sciences in nuclear physics and related area, including particle and astrophysics, to discuss future perspectives in the exa-scale computing. This is a satellite activity of the Fourth Joint Meeting of the Nuclear Physics Divisions of the American Physical Society and The Physical Society of Japan (October 8-11, 2014). See details here.

This meeting is supported by the JSPS Bilateral Program, “Open Partnership Joint Projects/Seminars”, for a promotion of international scientific exchanges between Japan and counterpart countries.