Polaronic features in the optical properties of the Holstein t-J model

被引:26
作者
Cappelluti, E.
Ciuchi, S.
Fratini, S.
机构
[1] CNR, INFM, SMC Res Ctr, I-00185 Rome, Italy
[2] Univ Roma La Sapienza, Dipartimento Fis, I-00185 Rome, Italy
[3] Univ Aquila, Ist Nazl Fis Mat, I-67010 Coppito, Italy
[4] Univ Aquila, Dipartimento Fis, I-67010 Coppito, Italy
[5] CNRS, Inst Neel, F-38042 Grenoble 9, France
[6] Univ Grenoble 1, F-38042 Grenoble 9, France
来源
PHYSICAL REVIEW B | 2007年 / 76卷 / 12期
关键词
D O I
10.1103/PhysRevB.76.125111
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
We derive an exact solution for the optical conductivity sigma(omega) of one hole in the Holstein t-J model in the framework of dynamical mean-field theory. We investigate the magnetic and phonon features associated with polaron formation as a function of the exchange coupling J, electron-phonon interaction lambda, and temperature. Our solution directly relates the features of the optical conductivity to excitations in the single-particle spectral function, revealing two distinct mechanisms of closing and filling of the optical pseudogap that take place upon varying the microscopic parameters. We show that the optical absorption at the polaron crossover is characterized by a coexistence of a magnon peak at low frequency and a broad polaronic band at higher frequency. An analytical expression for sigma(omega) valid in the polaronic regime is presented.
引用
收藏
页数:14
相关论文
共 51 条
[1]   OPTICAL CONDUCTIVITY IN THE T-J MODEL - SLAVE-BOSON, LARGE-N TECHNIQUE [J].
BANG, YY ;
KOTLIAR, G .
PHYSICAL REVIEW B, 1993, 48 (13) :9898-9901
[2]   Electrodynamics of high-Tc superconductors [J].
Basov, DN ;
Timusk, T .
REVIEWS OF MODERN PHYSICS, 2005, 77 (02) :721-779
[3]   Optical absorption and single-particle excitations in the two-dimensional Holstein t-J model [J].
Bauml, B ;
Wellein, G ;
Fehske, H .
PHYSICAL REVIEW B, 1998, 58 (07) :3663-3676
[4]  
Cappelluti E, 2002, PHYS REV B, V66, DOI 10.1103/PhysRevB.66.165102
[5]   Holes in the t-Jz model:: a diagrammatic study [J].
Chernyshev, AL ;
Leung, PW .
PHYSICAL REVIEW B, 1999, 60 (03) :1592-1606
[6]   Dynamical mean-field theory of the small polaron [J].
Ciuchi, S ;
dePasquale, F ;
Fratini, S ;
Feinberg, D .
PHYSICAL REVIEW B, 1997, 56 (08) :4494-4512
[7]   CORRELATED ELECTRONS IN HIGH-TEMPERATURE SUPERCONDUCTORS [J].
DAGOTTO, E .
REVIEWS OF MODERN PHYSICS, 1994, 66 (03) :763-840
[8]   Anisotropic electromagnetic response of lightly doped La2-xSrxCuO4 within the CuO2 planes -: art. no. 077004 [J].
Dumm, M ;
Komiya, S ;
Ando, Y ;
Basov, DN .
PHYSICAL REVIEW LETTERS, 2003, 91 (07)
[9]   OPTICAL-EXCITATION OF POLARONIC IMPURITIES IN LA2CUO4+Y [J].
FALCK, JP ;
LEVY, A ;
KASTNER, MA ;
BIRGENEAU, RJ .
PHYSICAL REVIEW B, 1993, 48 (06) :4043-4046
[10]   Optical properties of small polarons from dynamical mean-field theory [J].
Fratini, S. ;
Ciuchi, S. .
PHYSICAL REVIEW B, 2006, 74 (07)