Department of Physics, Indian Institute of Technology, Kharagpur, India.
Phys Rev Lett. 2011 Jun 10;106(23):236405. doi: 10.1103/PhysRevLett.106.236405.
Recent experiments on 2H-TaSe(2) contradict the long-held view of the charge density wave arising from a nested band structure. An intrinsically strong coupling view, involving a charge density wave state arising as a Bose condensation of preformed excitons emerges as an attractive, albeit scantily investigated alternative. Using the local density approximation plus multiorbital dynamic mean field theory, we show that this scenario agrees with a variety of normal state data for 2H-TaSe(2). Based thereupon, the ordered states in a subset of dichalcogenides should be viewed as instabilities of a correlated, preformed excitonic liquid.
最近对 2H-TaSe(2) 的实验结果与电荷密度波源于嵌套能带结构的长期观点相矛盾。一个内在的强耦合观点，涉及到作为预形成激子玻色凝聚而出现的电荷密度波态，作为一种有吸引力的但研究甚少的替代方案出现。我们使用局域密度近似加多轨道动态平均场理论，表明这种情况与 2H-TaSe(2) 的各种正常状态数据一致。在此基础上，应该将一组二卤代物中的有序态视为相关的、预形成激子液体的不稳定性。
