Some general conditions for hidden Fermi surface nesting

Abstract

Certain low-dimensional metals exhibit charge density wave (CDW) instabilities although their individual Fermi surfaces do not have the nesting responsible for the observed CDW's. This phenomenon is explained in terms of the conept of hidden Fermi surface nesting. In order to find general conditions leading to hidden Fermi surface nesting in low-dimensional systems, we examined the electronic structures of two widely different classes of compounds, i.e., the inorganic transition-metal oxide Sr3V207 and the organic conducting salts (BEDT-TTF)2Re04 and (BEDT-TTF)4Pt(C204)2.

Characterisation of the Fermi surface and phase transitions of (BEDO-TTF)2 ReO4�(H2O) by physical property measurements and electronic band structure calculations

“…When the temperature is lowered, donor molecules may undergo slight local displacements to adjust to the ensuing decrease in the unit cell volume thereby changing the extend of the 1D or 2D character of the Fermi surface. The 'wavy stripes' of is supported on the basis of the hidden nesting concept [ 15,18]. The SDW formation removes some of the Fermi surfaces, which explains the finding from the Hall effect measurements (see Fig.…”

“…The latter are found by combining the individual 2D Fermi surface together and neglecting the surface noucrossings. In understanding the CDW instabilities of the organic conducting salts (BEDT-TTF)2ReO4 [16] and (BEDT-TTF),Pt(C204) [17], the hidden nesting concept has also been found essential [18]. Thus, it is important to probe whether or not the hidden nesting concept is also responsible for the increase of the resistivity below 35 K of the 2D metal (BEDO-TTF)zReO4.…”

Density-wave instability inα−(BEDT-TTF)2KHg(SCN)4Foury-Leylekian1, Pouget2, Lee3 et al. 2010Phys. Rev. B273340View full textAdd to dashboardCite

“…However, in contrast with the situation in the last salt, the CDW transition of ͑BEDT-TTF͒ 2 ReO 4 stabilizes an insulating ground state via a hidden Fermi surface nesting mechanism of the total Fermi surface achieved by a first-order phase transition. 84 In these BEDT-TTF salts, superconductivity occurs when the CDW ground state is removed under pressure. In other BEDT-TTF salts which do not exhibit these 1D electronic features such as the phases, 4k F like charge ordering phenomena are observed.…”

An In-Depth Correlation of the Perturbation of the Organic–Inorganic Interface Topology, Electronic Structure, and Transport Properties within an Extended Series of 21 Metallic Pseudopolymorphs, ″-(BEDT-TTF)4⋅(guest)n⋅[Re6Q6Cl8], (Q=S, Se)

“…This kind of ™assisted∫ (because it needs some structural change to conveniently modify the Fermi surface) or ™hidden∫ (because it is not obvious from the room-temperature Fermi surface) nesting mechanism is thought to be at the origin of the metal ± insulator transition in (BEDT-TTF) 2 ReO 4 . [21] At this point the question is, given the similar topology of the crystal structures why do not all three of these phases undergo such a distortion and therefore have a metal ± insulator transition? For a Fermi surface containing four warped open lines, like that in Figure 10c, the existence of a Fermi surface driven metal ± insulator transition implies that one nesting vector allows the simultaneous superposition of the two lower and two upper lines.…”