Jeckelmann Eric
Fachbereich Physik, Philipps-Universität, D-35032 Marburg, Germany.
Phys Rev Lett. 2002 Dec 2;89(23):236401. doi: 10.1103/PhysRevLett.89.236401. Epub 2002 Nov 15.
The density-matrix renormalization group is used to study the phase diagram of the one-dimensional half-filled Hubbard model with on-site (U) and nearest-neighbor (V) repulsion and hopping t. A critical line V(c)(U) approximately U/2 separates a Mott insulating phase from a charge-density-wave phase. The formation of bound charge excitations for V>2t changes the phase transition from continuous to first-order at a tricritical point U(t) approximately 3.7t, V(t)=2t. A frustrating effective antiferromagnetic spin coupling induces a bond-order-wave phase on the critical line V(c)(U) for U(t)<U less, similar 7t.
密度矩阵重整化群被用于研究具有在位（U）和最近邻（V）排斥以及跳跃t的一维半填充哈伯德模型的相图。一条临界线V(c)(U)≈U/2将莫特绝缘相和电荷密度波相分隔开。对于V>2t，束缚电荷激发的形成将在一个三临界点U(t)≈3.7t、V(t)=2t处的相变从连续转变为一级相变。一种令人沮丧的有效反铁磁自旋耦合在临界线V(c)(U)上诱导出一个键序波相，其中U(t)<U≤7t。
