250 research outputs found
自己エネルギー汎関数法 : モット転移の解析
No full textこの論文は国立情報学研究所の電子図書館事業により電子化されました。自己エネルギー汎関数法(self-energy functional approach)は、ラッティンジャー・ワードの定式化に基づく変分原理を利用して、対象とする系の自己エネルギーを変分的に決定する近似法である。ここで、試行関数の役割をする自己エネルギーは、"参照系"と呼ばれる容易に解くことのできる系で求める。すなわち、代理の系でパラメータを変化させて求めた自己エネルギーの中から、目的の系の物性を上手く再現するものを変分原理に基づいて探す。このとき、参照系は、対象とする系と同じ相互作用項を持つ必要がある。この方法の利点の一つに、参照系で求めた試行的な自己エネルギーを通して、相互作用の効果を非摂動論的に扱えることが挙げられる。また、ここで用いる変分原理は、系のグリーン関数が満たすべき因果律や保存則を保証する。これらの利点は、モット転移などの電子相関によって生じる様々な現象を調べるのに有効である。本稿では、自己エネルギー汎関数法について解説した後、モット転移に関する最近のトピックスについてこの方法を用いて行った研究を紹介する
Detecting partial synchrony in a complex oscillatory network using pseudo-vortices
No full textPartial synchronization is characteristic phase dynamics of coupled
oscillators on various natural and artificial networks, which can remain
undetected due to the complexity of the systems. With an analogy between
pairwise asynchrony of oscillators and topological defects, i.e., vortices, in
the two-dimensional XY spin model, we propose a robust and data-driven method
to identify the partial synchronization on complex networks. The proposed
method is based on an integer matrix whose element is pseudo-vorticity that
discretely quantifies asynchronous phase dynamics in every two oscillators,
which results in graphical and entropic representations of partial synchrony.
As a first trial, we apply our method to 200 FitzHugh-Nagumo neurons on a
complex small-world network. Partially synchronized chimera states are revealed
by discriminating synchronized states even with phase lags. Such phase lags
also appear in partial synchronization in chimera states. Our topological,
graphical, and entropic method is implemented solely with measurable phase
dynamics data, which will lead to a straightforward application to general
oscillatory networks including neural networks in the brain.Comment: 9 pages, 5 figure
Thermodynamic properties of two-component fermionic atoms trapped in a two-dimensional optical lattice
No full textTime-of-Flight Imaging Method to Observe Signatures of Antiferromagnetically Ordered States of Fermionic Atoms in an Optical Lattice
No full textAn Energy‐Tunable Dual Emission Mechanism of the Hybridized Local and Charge Transfer (HLCT) and the Excited State Conjugation Enhancement (ESCE)
No full textThis is the accepted version of the following article: Suga Kensuke, Ochiai Keisuke, Yoneda Yusuke, et al. An Energy‐Tunable Dual Emission Mechanism of the Hybridized Local and Charge Transfer (HLCT) and the Excited State Conjugation Enhancement (ESCE). Chemistry – A European Journal, e202404376 (2024), which has been published in final form at https://doi.org/10.1002/chem.202404376. This article may be used for non-commercialpurposes in accordance with the Wiley Self-ArchivingPolicy [https://authorservices.wiley.com/author-resources/Journal-Authors/licensing/self-archiving.html]Molecular design of dual-fluorescent probes requires precise adjustment of the energy levels of two excited states and the energy barrier between them. While the hybridized local and charge-transfer (HLCT) state has been recently focused as an important excited state for high emission efficiency with a tunable energy level, a dual emission involving the HLCT state has been only achieved with the excited-state intramolecular proton transfer (ESIPT) system. Here, a series of dual-fluorescent molecules involving an HLCT excited state with the excited-state conjugation enhancement (ESCE) motif is presented as the first case. The energy level of the HLCT state has been adjusted by changing substituents and solvents, separately from the ESCE energy level. The HLCT-ESCE molecular design with tunable fluorescence properties proposes a new strategy for the development of advanced fluorescent probes
Datasets produced by SCALE-GM in QBO-like oscillation experiments.
No full textData produced by SCALE-GM and used in the manuscript submitted to the AMS journal Monthly Weather Review.
Authors:
Hiroki Kashimura, Hisashi Yashiro, Seiya Nishizawa, Hirofumi Tomita, Kensuke Nakajima, Masaki Ishiwatari, Yoshiyuki O. Takahashi, and Yoshi-Yuki Hayashi
Corresponding Author:
Hiroki Kashimura ([email protected])
Manuscript Title:
Dependence of a QBO-like oscillation on time-step intervals in a non-hydrostatic general circulation model
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COLOR SUPERFLUID AND TRIONIC STATE OF ATTRACTIVE THREE-COMPONENT LATTICE FERMIONIC ATOMS AT FINITE TEMPERATURES
No full text We investigate the finite-temperature properties of attractive three-component (colors) fermionic atoms in optical lattices using a self-energy functional approach. As the strength of the attractive interaction increases in the low temperature region, a second-order transition occurs from a Fermi liquid to a color superfluid (CSF). In the strong attractive region, a first-order transition occurs from a CSF to a trionic state. In the high temperature region, a cross-over between a Fermi liquid and a trionic state is observed with increasing the strength of the attractive interaction. The cross-over region for fixed temperature is almost independent of filling. </jats:p
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