U(1)xSU(2) Chern-Simons gauge theory of underdoped cuprate superconductors

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	U(1)xSU(2) Chern-Simons gauge theory of underdoped cuprate superconductors
	Marchetti, PA; Su, ZB; Yu, L; Marchetti, PA , Univ Padua, Dipartimento Fis, INFN, I-35131 Padua, Italy.
刊名	PHYSICAL REVIEW B
	1998
卷号	58 期号:9 页码:5808-5824
关键词	T-j Model Dimensional Hubbard-model Quantum-field Theory Non-abelian Bosonization Valence-bond State Spin Dynamics 2 Dimensions Electronic-structure Critical Exponents c Superconductors
ISSN号	0163-1829
英文摘要	The Chern-Simons bosonization with U(1)xSU(2) gauge field is applied to the two-dimensional t-J model in the limit t much greater than J, to study the normal-state properties of underdoped cuprate superconductors. We prove the existence of an upper bound on the partition function for holons in a spinon background and we find the optimal spinon configuration saturating the upper bound on average-a coexisting flux phase and s+id-like resonating-valence-bond state. After neglecting the feedback of holon fluctuations on the U(1) field B and spinon fluctuations on the SU(2) field V, the holon field is a fermion and the spinon field is a hard-core boson. Within this approximation we show that the B field produces a rr flux phase for the holons, converting them into Dirac-like fermions, while the V field, taking into account the feedback of holons produces a gap for the spinons vanishing in the zero-doping limit. The nonlinear-a model with a mass term describes the crossover from the short-ranged antiferromagnetic (AF) state in doped samples to long-range AF order in reference compounds. Moreover, we derive a low-energy effective action in terms of spinons, holons and a self-generated U(1) gauge field. Neglecting the gauge fluctuations, the holons are described by the Fermi-liquid theory with a Fermi surface consisting of four "half-pockets" centered at (+/-pi/2,+/-pi/2) and one reproduces the results for the electron spectral function obtained in the mean-field approximation, in agreement with the photoemission data on underdoped cuprates: The gauge fluctuations are not confining due to coupling to holons, but nevertheless yield an attractive interaction between spinons and holons leading to a bound state with electron quantum numbers. The renormalization effects due to gauge fluctuations give rise to non-Fermi-liquid behavior for the composite electron, in certain temperature range showing the linear in T resistivity. This formalism provides a new interpretation of the spin gap in the underdoped superconductors (mainly due to the short-ranged AF order) and predicts that the minimal gap for the physical electron is proportional to the square root of the doping concentration. Therefore the gap does not vanish in any direction. All these predictions can be checked explicitly in experiment.
学科主题	Physics
URL标识	查看原文
WOS记录号	WOS:000075720100095
公开日期	2012-08-29
内容类型	期刊论文
源URL	[http://ir.itp.ac.cn/handle/311006/12271]
专题	理论物理研究所_理论物理所1978-2010年知识产出
通讯作者	Marchetti, PA , Univ Padua, Dipartimento Fis, INFN, I-35131 Padua, Italy.
推荐引用方式 GB/T 7714	Marchetti, PA,Su, ZB,Yu, L,et al. U(1)xSU(2) Chern-Simons gauge theory of underdoped cuprate superconductors[J]. PHYSICAL REVIEW B,1998,58(9):5808-5824.
APA	Marchetti, PA,Su, ZB,Yu, L,&Marchetti, PA , Univ Padua, Dipartimento Fis, INFN, I-35131 Padua, Italy..(1998).U(1)xSU(2) Chern-Simons gauge theory of underdoped cuprate superconductors.PHYSICAL REVIEW B,58(9),5808-5824.
MLA	Marchetti, PA,et al."U(1)xSU(2) Chern-Simons gauge theory of underdoped cuprate superconductors".PHYSICAL REVIEW B 58.9(1998):5808-5824.