Debnath Debika, Malik M Zahid, Chatterjee Ashok
School of Physics, University of Hyderabad, Hyderabad, 500046, India.
Sci Rep. 2021 Jun 10;11(1):12305. doi: 10.1038/s41598-021-91604-6.
The nature of phase transition from an antiferromagnetic SDW polaronic Mott insulator to the paramagnetic bipolaronic CDW Peierls insulator is studied for the half-filled Holstein-Hubbard model in one dimension in the presence of Gaussian phonon anharmonicity. A number of unitary transformations performed in succession on the Hamiltonian followed by a general many-phonon averaging leads to an effective electronic Hamiltonian which is then treated exactly by using the Bethe-Ansatz technique of Lieb and Wu to determine the energy of the ground state of the system. Next using the Mott-Hubbard metallicity condition, local spin-moment calculation, and the concept of quantum entanglement entropy and double occupancy, it is shown that in a plane spanned by the electron-phonon coupling coefficient and onsite Coulomb correlation energy, there exists a window in which the SDW and CDW phases are separated by an intermediate phase that is metallic.
在存在高斯声子非谐性的情况下，针对一维半填充的霍斯坦 - 哈伯德模型，研究了从反铁磁自旋密度波极化子莫特绝缘体到顺磁双极化子电荷密度波派尔斯绝缘体的相变性质。对哈密顿量相继进行一系列幺正变换，然后进行一般的多声子平均，得到一个有效的电子哈密顿量，接着通过使用利布和吴的贝塞耳 ansatz 技术精确处理该哈密顿量，以确定系统基态的能量。接下来，利用莫特 - 哈伯德金属性条件、局域自旋矩计算以及量子纠缠熵和双占据的概念，表明在由电子 - 声子耦合系数和在位库仑关联能所构成的平面中，存在一个窗口，其中自旋密度波和电荷密度波相被一个金属性的中间相分隔开。
