Simultaneous competition and coexistence between charge-density waves and reentrant superconductivity in the pressure-temperature phase diagram of the molecular conductor TTF
Simultaneous competition and coexistence between charge-density waves and reentrant superconductivity in the pressure-temperature phase diagram of the molecular conductor TTF
复制标题
分子导体TTF压力-温度相图中电荷密度波与折返超导的同时竞争与共存
DOI：
10.1103/physrevb.42.3935
复制
发表时间：
1990
期刊：
影响因子：
--
通讯作者：
P. Cassoux
中科院分区：
文献类型：
--
作者：
L. Brossard;M. Ribault;L. Valade;P. Cassoux
通过高达14千巴的交流电阻率测量，仔细确定了准一维分子超导体TTF[Ni(dmit${)}_{2}$${]}_{2}$的压力 - 温度相图。压力升高会在高温金属与连续的金属或半金属、半导体以及再进入超导基态之间引发电子相变。将这个不寻常的相图与TTF[Pd(dmit${)}_{2}$${]}_{2}$的相图进行了比较。结合常压下的电荷密度波（CDW）不稳定性对其进行了讨论，其波矢可以通过一种涉及受体层的最高占据分子轨道和最低未占据分子轨道的原始导带结构很好地解释。证实了超导温度随压力升高而缓慢上升。有人提出，超导性与高温电荷密度波不稳定性共存，并且与低温电荷密度波涨落存在微弱竞争；这些电荷密度波影响费米面的不同部分。
The pressure-temperature phase diagram of the quasi-one-dimensional molecular superconductor TTF [Ni(dmit${)}_{2}$${]}_{2}$ has been carefully determined by ac resistivity measurements up to 14 kbar. Increasing pressures induce electronic phase transitions between a high-temperature metal and successive, metallic or semimetallic, semiconducting and reentrant superconducting ground states. This unusual phase diagram is compared with that of TTF [Pd(dmit${)}_{2}$${]}_{2}$. It is discussed in connection with ambient-pressure charge-density-wave (CDW) instabilities, the wave vector of which can be well accounted for by an original conduction-band structure involving both the highest occupied molecular orbitals and the lowest unoccupied molecular orbitals of the acceptor slabs. It is confirmed that the superconducting temperature increases slowly with increasing pressure. It is suggested that the superconductivity coexists with a high-temperature CDW instability and is in weak competition with low-temperature CDW fluctuations; these CDW's affect different parts of the Fermi surface.