Dual chiral density wave induced oscillating Casimir effect

Fujii, Daisuke; Nakayama, Katsumasa*; Suzuki, Kei

Physical Review D, 110(1), p.014039_1 - 014039_15, 2024/07

https://doi.org/10.1103/PhysRevD.110.014039

The Casimir effect is known to be induced from photon fields confined by a small volume, and also its fermionic counterpart has been predicted in a wide range of quantum systems. Here, we investigate what types of Casimir effects can occur from quark fields in dense and thin quark matter. In particular, in the dual chiral density wave, which is a possible ground state of dense quark matter, we find that the Casimir energy oscillates as a function of the thickness of matter. This oscillating Casimir effect is regarded as an analog of that in Weyl semimetals and is attributed to the Weyl points in the momentum space of quark fields. In addition, we show that an oscillation is also induced from the quark Fermi sea, and the total Casimir energy is composed of multiple oscillations.

Symposium on "Science of nuclear fuel cycle and backend; Research and education" with a memory of Professor Joonhong Ahn, the University of California, Berkeley

Nakayama, Shinichi; Okumura, Masahiko*; Nagasaki, Shinya*; Enokida, Yoichi*; Umeki, Hiroyuki*; Takase, Hiroyasu*; Kawasaki, Daisuke*; Hasegawa, Shuichi*; Furuta, Kazuo*

Genshiryoku Bakkuendo Kenkyu (CD-ROM), 23(2), p.131 - 148, 2016/12

http://nuce.aesj.or.jp/jnuce/vol23/Jnuce-Vol23-2-p131-148.pdf

A symposium "Science of nuclear fuel cycle and backend - Research and education -" was held at the Univer-sity of Tokyo in June 25, 2016. This aimed at developing the research on nuclear fuel cycle and backend. The time and the number of participants of the symposium were limited, but the active discussion was conducted, and the common perception for the future was shared among the experienced participants in those fields. This paper provides the discussions made in the symposium, and also, as a memory to Professor Ahn, the University of California, Berkeley, his prominent achievements in academic research and education.

Horonobe Underground Research Laboratory Project; Investigation report for the 2011 fiscal year

Nakayama, Masashi; Amano, Kenji; Tokiwa, Tetsuya; Yamamoto, Yoichi; Oyama, Takuya; Amano, Yuki; Murakami, Hiroaki; Inagaki, Daisuke; Tsusaka, Kimikazu; Kondo, Keiji; et al.

JAEA-Review 2012-035, 63 Pages, 2012/09

JAEA-Review-2012-035.pdf:12.23MB

The Horonobe Underground Research Laboratory Project is planned to extend over a period 20 years. The investigations will be conducted in three phases, namely "Phase 1: Surface-based investigations", "Phase 2: Construction Phase" (investigations during construction of the underground facilities) and "Phase 3: Operation phase"(research in the underground facilities). This report summarizes the results of the investigations for the 2011 fiscal year (2011/2012). The investigations, which are composed of "Geoscientific research" and "R&D on geological disposal technology", were carried out according to "Horonobe Underground Research Laboratory Project Investigation Program for the 2011 Fiscal year". The results of these investigations, along with the results which were obtained in other departments of Japan Atomic Energy Agency (JAEA), are properly offered to the implementations and the safety regulations. For the sake of this, JAEA has proceeded with the project in collaboration with experts from domestic and overseas research organisations.

Application study on low alkaline cementitious materials for deep geological repository of high level radioactive wastes, 2; Organization of previous finding and understanding of material properties of low alkaline cement (Joint research)

Kobayashi, Yasushi; Yamada, Tsutomu; Naito, Morimasa; Yui, Mikazu; Nakayama, Masashi; Sato, Haruo; Nishida, Takahiro*; Hironaga, Michihiko*; Yamamoto, Takeshi*; Sugiyama, Daisuke*; et al.

JAEA-Research 2009-013, 70 Pages, 2009/06

JAEA-Research-2009-013.pdf:8.85MB

Cementitious materials will be used to ensure construction and operational safety and work efficiency in a deep geological repository. The low alkaline cement has been developed to reduce uncertainties due to hyper alkaline for the long-term safety performance of the repository system. Functions of cementitious material required in each phase of repository construction, operation and closure were summarized in a separate report entitled "Application Study on Low Alkaline Cementitious Materials for Deep Geological Repository of High Level Radioactive Wastes (Phase I) "In this report, properties of low alkaline cement/concrete which have been developed both at home and abroad, and recipes of the low alkaline concrete taken account of application to the repository component have been investigated. Fresh and hardened properties of the low alkaline cement are equivalent to the OPC and the low alkaline cement has an advantage over OPC in terms of leaching resistance. The HFSC developed by JAEA, which belongs to a pozzolanic type low alkaline cement will be able to apply to the shotcrete and the lining concrete by choosing an adequate recipe. Clarification of influences of the chemical composition of groundwater on leachate properties of the hydrates, examination of pH measurement of cement leachate, evaluation of corrosion behavior of rebar embedded in the HFSC concrete are raised as open questions for future activities.

Casimir effect in dual chiral density waves

Fujii, Daisuke; Suzuki, Kei; Nakayama, Katsumasa*

no journal, , 

In this talk, we discuss the discovery of a new Casimir effect that emerges from the quark field in dense, thin quark matter when the magnetic field is zero or non-zero. Surprisingly, in the dual chiral density wave (DCDW) phase, a candidate ground state of dense quark matter, the Casimir energy oscillates as a function of thickness. This finding highlights a novel oscillating Casimir phenomenon driven by QCD dynamics in extreme conditions.

Casimir effect at finite density

Suzuki, Kei; Fujii, Daisuke; Nakayama, Katsumasa*

no journal, , 

In this talk, I discuss the general features of the Casimir effect induced from quantum fields at finite chemical potential, particularly at finite density. Historically, the thermal Casimir effect has been well-established by the cooperation between theory and experiment, whereas its counterpart at finite chemical potential is still not. This is because it is usually difficult to control the chemical potential of photons in equilibrium experimentally. On the other hand, if one focuses on fermionic systems, their chemical potentials may be a tunable parameter for the Casimir effect. In addition, various quantum many-body phenomena realized at finite fermion density can modify the typical property of the Casimir effect. Within some theoretical frameworks, we evaluate the Casimir energy for Dirac fields at finite density and particularly show an oscillatory behavior as a function of the separation of boundary conditions or the chemical potential. As physical and realistic examples of the Casimir effect at finite chemical potential, I discuss applications to fermion fields inside thin dense quark matter in hadron physics and to Dirac/Weyl semimetal thin films in solid-state physics. Such materials will be platforms to examine the fermionic Casimir effect at finite chemical potential.