caa a22 4500 445867167 CHVBK 20180317145501.0 cr unu---uuuuu 170323e20111201xx s 000 0 eng 10.1140/epjd/e2011-20339-1 doi (NATIONALLICENCE)springer-10.1140/epjd/e2011-20339-1 Cheng Z. School of Physics, Huazhong University of Science and Technology, 430074, Wuhan, P.R. China aut Condensation state of ultra-cold Bose atomic gases with pure gradient interactions with negative coefficient [Elektronische Daten] [Z. Cheng] Within the framework of quantum field theory, we find that uniform Bose atomic gases with pure gradient interactions with negative coefficient can undergo a Bardeen-Cooper-Schrieffer (BCS) condensation below a critical temperature. In the BCS condensation state, bare atoms with opposite wave vectors are bound into pairs, and unpaired bare atoms are transformed into a new kind of quasi-particle, i.e. the dressed atom. The atom-pair system is a condensate or a superfluid and the dressed-atom system is a normal fluid. At absolute zero temperature the condensate possesses a lowest negative energy. When the total interaction strength of atoms is large enough, the energy of the condensate is a monotonically increasing function of temperature and interaction strength. The critical temperature and the effective mass of dressed atoms are derived analytically. The transition from the BCS condensation state to the normal state is a first-order phase transition. EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg, 2011 The European Physical Journal D Springer-Verlag 65/3(2011-12-01), 523-532 1434-6060 65:3<523 2011 65 10053 https://doi.org/10.1140/epjd/e2011-20339-1 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1140/epjd/e2011-20339-1 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Cheng Z. School of Physics, Huazhong University of Science and Technology, 430074, Wuhan, P.R. China aut NATIONALLICENCE 773 0- The European Physical Journal D Springer-Verlag 65/3(2011-12-01), 523-532 1434-6060 65:3<523 2011 65 10053 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer