SPIN LADDERS WITH SPIN GAPS - A DESCRIPTION OF A CLASS OF CUPRATES

被引:363
作者
GOPALAN, S
RICE, TM
SIGRIST, M
机构
[1] Theoretische Physik, Eidgenössische Technische Hochschule Hönggerberg
来源
PHYSICAL REVIEW B | 1994年 / 49卷 / 13期
关键词
D O I
10.1103/PhysRevB.49.8901
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
We investigate the magnetic properties of the Cu-O planes in stoichiometric Srn-1Cun+1O2n (n = 3,5,7,...) which consist of CuO double chains periodically intergrown within the CuO2 planes. The double chains break up the two-dimensional antiferromagnetic planes into Heisenberg spin ladders with n(r) = 1/2 (n - 1) rungs and n(l) = 1/2 (n + 1) legs and described by the usual antiferromagnetic coupling J inside each ladder and a weak and frustrated interladder coupling J'. The resulting lattice is a new two-dimensional trellis lattice. We first examine the spin excitation spectra of isolated quasi-one-dimensional Heisenberg ladders which exhibit a gapless spectrum when n, is even and n(l) is odd (corresponding to n = 5, 9,...) and a gapped spectrum when n(r) is odd and n(l) is even (corresponding to n = 3,7,...). We use the bond operator representation of quantum S = 1/2 spins in a mean-field treatment with self-energy corrections and obtain a spin gap of almost-equal-to 1/2J for the simplest single-rung ladder (n = 3), in agreement with numerical estimates. We also present results of the dynamical structure factor S(q, omega). The spin gap decreases considerably on increasing the width of the ladders. For a double ladder with four legs and three rungs (n = 7) we obtain a spin gap of only 0.1J. However, a frustrated coupling, such as that of a trellis lattice, introduced between the double ladders leads to an enhancement of the gap. Thus stoichiometric Srn-1Cun+1O2n compounds with n = 3,7,11,..., will be frustrated quantum antiferromagnets with a quantum-disordered or spin-liquid ground state.
引用
收藏
页码:8901 / 8910
页数:10
相关论文
共 13 条
  • [1] Anderson P. W., 1963, MAGNETISM, V1
  • [2] THE RESONATING VALENCE BOND STATE IN LA2CUO4 AND SUPERCONDUCTIVITY
    ANDERSON, PW
    [J]. SCIENCE, 1987, 235 (4793) : 1196 - 1198
  • [3] EXCITATION SPECTRUM OF HEISENBERG SPIN LADDERS
    BARNES, T
    DAGOTTO, E
    RIERA, J
    SWANSON, ES
    [J]. PHYSICAL REVIEW B, 1993, 47 (06) : 3196 - 3203
  • [4] SUPERCONDUCTIVITY IN LADDERS AND COUPLED PLANES
    DAGOTTO, E
    RIERA, J
    SCALAPINO, D
    [J]. PHYSICAL REVIEW B, 1992, 45 (10): : 5744 - 5745
  • [5] FRAGA S, 1976, HDB ATOMIC DATA, P195
  • [6] A NEW HOMOLOGOUS SERIES SRN-1CUN+1O2N FOUND IN THE SRO-CUO SYSTEM TREATED UNDER HIGH-PRESSURE
    HIROI, Z
    AZUMA, M
    TAKANO, M
    BANDO, Y
    [J]. JOURNAL OF SOLID STATE CHEMISTRY, 1991, 95 (01) : 230 - 238
  • [7] HIRSCH R, 1988, THESIS U KOLN
  • [8] RENORMALIZATION FROM DENSITY-FUNCTIONAL THEORY TO STRONG-COUPLING MODELS FOR ELECTRONIC STATES IN CU-O MATERIALS
    HYBERTSEN, MS
    STECHEL, EB
    SCHLUTER, M
    JENNISON, DR
    [J]. PHYSICAL REVIEW B, 1990, 41 (16): : 11068 - 11072
  • [9] PHASE-DIAGRAM OF S=1/2 ANTIFERROMAGNETIC HEISENBERG-MODEL ON A DIMERIZED SQUARE LATTICE
    KATOH, N
    IMADA, M
    [J]. JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 1993, 62 (10) : 3728 - 3740
  • [10] SUPERCONDUCTIVITY, SPIN GAPS AND LUTTINGER LIQUIDS IN A CLASS OF CUPRATES
    RICE, TM
    GOPALAN, S
    SIGRIST, M
    [J]. EUROPHYSICS LETTERS, 1993, 23 (06): : 445 - 449