| Original Articles |
|
|
|
|
Quantum Tricritical Point in the Spin-Boson Model with an Ohmic Bath |
| CHEN Wen;CHEN Zhi-De |
| Department of Physics, Jinan University, Guangzhou 510632 |
|
| Cite this article: |
|
CHEN Wen, CHEN Zhi-De 2007 Chin. Phys. Lett. 24 1140-1143 |
|
|
|
|
Abstract The dynamics of the spin-boson model with an Ohmic bath at finite temperature is studied by a variational calculation. Numerical solution of the self-consistent equation derived from the variational method shows that the transition from incoherent to coherent phases is discontinuous. It indicates that (T=0,s=1) is a tricritical point, i.e. the transition changes from continuous to discontinuous by tuning from T=0 to T≠0. The discontinuous transition at finite temperature is analysed by Landau theory and the relation to the experimental observation on the coherent state is also discussed.
|
| Keywords:
03.65.Yz
03.65.Xp
73.40.Gk
|
|
|
Received: 18 October 2006
Published: 23 April 2007
|
|
| PACS: |
03.65.Yz
|
(Decoherence; open systems; quantum statistical methods)
|
| |
03.65.Xp
|
(Tunneling, traversal time, quantum Zeno dynamics)
|
| |
73.40.Gk
|
(Tunneling)
|
|
|
|
|
|
[1] Leggett A J, Chakravarty S, Dorsey A T, Fisher M P A, Garg Aand Zwerger W 1987 Rev. Mod. Phys. 59 1 and references therein
[2] Weiss U 1999 Quantum Dissipative Systems (Singapore:World Scientific)
[3] Bray A J and Moore M A 1982 Phys. Rev. Lett. 49 1545
[4] Hewson A C and Newns D M 1980 J. Phys. C 13 4477
[5] Zwerger W 1983 Z. Phys. B 53 53
[6] Silbey R and Harris R A 1984 J. Chem. Phys. 80 2615
[7] Chen H, Zhang Y M and Wu X 1989 Phys. Rev. B 39 546
[8] Nie Y H, Liang J J, Shi Y L and Liang J Q 2005 Eur.Phys. J. B 43 125
[9] Bulla R, Tong N H and Vojta M 2003 Phys. Rev. Lett. 91 170601 Bulla R, Tong N H and Vojta M 2005 Phys. Rev. B 71 045122
[10] Chin A and Turlakov M 2006 Phys. Rev. B 73 075311
[11]Tong N H and Vojta M 2006 Phys. Rev. Lett. 97 016802
[12]L"u Z G and Zheng H 2007 Phys. Rev. B 75 054302
[13] Spohn H and D"umcke R 1985 J. Statist. Phys. 41 389
[14] Kehrein S K and Mielke A 1996 Phys. Lett. A 219 313
[15]Vojta M, Tong N H and Bulla R 2005 Phys. Rev. Lett. 94 070604
[16] Sachdev S 1999 Quantum Phase Transition (Cambridge:Cambridge University)
[17] Vojta M 2003 Rep. Prog. Phys. 66 2069
[18] Goldenfeld N 1992 Lectures on Phase Transition and theRenormalization Group (Cambridge: Addison-Wesley)
[19] Chaikin P M and Lubensky T C 1995 Principles ofCondensed Matter Physics (Cambridge: Cambridge University Press)
[20] Feng D and Jin G J 2003 Condensed Matter Physics (Beijing: Higher Education Press) vol I (in Chinese)
[21] Wong H and Chen Z D cond-mat/0609201
[22] Tong N H and Pu F C 2000 Phys. Rev. B 62 9425
[23]Tong N H, Shen S Q and Pu F C 2001 Phys. Rev. B 64235109
[24] Leuenberger N and Loss D 2001 Nature 410 789
[25] Hou B P, Wang S J, Yu W L, Sun W L and Wang G 2004 Chin.Phys. Lett. 21 2334
[26] Wang W G 2003 Chin. Phys. Lett. 22 3009 |
|
Viewed |
|
|
|
Full text
|
|
|
|
|
Abstract
|
|
|
|
|
