Upcoming Seminars

Date/Place Jun. 27th(Tue.) 15:30-16:30 / H711
Name Tsuyoshi Yokoya (Osaka University)
Title Entanglement Entropy for 2D Gauge Theories with Matters
Abstract We investigate the entanglement entropy in 1+1-dimensional SU(N) gauge theories with matter fields using the lattice regularization. Here we use extended Hilbert space definition for entanglement entropy, which contains three contributions; (1) classical Shannon entropy associated with superselection sector distribution, where sectors are labelled by irreducible representations of boundary penetrating fluxes, (2) logarithm of the dimensions of their representations, which is associated with “color entanglement”, and (3) EPR Bell pairs, which give “genuine” entanglement. We explicitly show that entanglement entropies (1) and (2) above indeed appear for various multiple “meson” states in gauge theories with matter fields. Furthermore, we employ transfer matrix formalism for gauge theory with fundamental matter field and analyze its ground state using hopping parameter expansion (HPE). We evaluate the entanglement entropy for the ground state and show that all (1), (2), (3) above appear in the HPE, though the Bell pair part (3) appears in higher order than (1) and (2) do. With these results, we discuss how the ground state entanglement entropy in the continuum limit can be understood from the lattice ground state obtained in the HPE.

 

Date/Place Jul. 4th(Tue.) 15:30-17:00 / Nambu Hall
Name Masatoshi Sato (YITP, Kyoto University)
Title K理論とトポロジカル結晶物質
Abstract 多数の自由度が集まることによって元の構成要素がもち得なかった性質が生じる。場の量子論における重要な問題の一つはこのような「相」としてどのようなものがあるかを明らかにすることである。トポロジカル相とは、そのような相の一つであり、絶縁体や超伝導体のようなギャップのある系だけでなく、電子系でワイルフェルミンやディラックフェルミオンを実現する半金属などギャップのない系でも実現されていることが知られている。本講演では、K理論を用いたトポロジカル物質の定式化および分類理論を紹介する。

 

Date/Place Jul. 11th(Tue.) 15:30-16:30 / H711
Name Ya-Juan Zheng (Osaka University)
Title TBA
Abstract TBA

 

Date/Place Jul. 18th(Tue.) 15:30-16:30 / H711
Name Yukio Kaneko (Tohoku University)
Title TBA
Abstract TBA

 

Date/Place Jul. 25th(Tue.) 15:30-16:30 / H711
Name Yusuke Taniguchi (University of Tsukuba)
Title TBA
Abstract TBA

 

Past Seminars