Slow Oscillations of Magnetoresistance in Quasi-Two-Dimensional Metals

Abstract

Slow oscillations of the interlayer magnetoresistance observed in the layered organic metal β-(BEDT-TTF) 2 IBr 2 are shown to originate from the slight warping of its Fermi surface rather than from independent small cyclotron orbits. Unlike the usual Shubnikov-de Haas effect, these oscillations are not affected by the temperature smearing of the Fermi distribution and can therefore become dominant at high enough temperatures. We suggest that the slow oscillations are a general feature of clean quasi-two-dimensional metals and discuss possible applications of the phenomenon.

Slow Oscillations of In-plane Magnetoresistance in Strongly Anisotropic Quasi-Two-Dimensional Rare-Earth Tritellurides

“…4, we conclude that these oscillations originate not from small FS pockets as usual SdH oscillations, but from the entanglement of close frequencies due to a finite t z , similar to that observed in the interlayer MR in the organic metal β-(BEDT-TTF) 2 IBr 2 [34]. The strong additional argument in favor of this origin of the observed slow oscillations is the very weak temperature dependence of their amplitude.…”

“…2 where we show the temperature evolution of slow oscillations for GdTe 3 and TbTe 3 . This suggests that the observed slow oscillations originate not from small FS pockets, but from the FS warping due to t z , similarly to the slow oscillations of interlayer MR in the organic superconductor β-(BEDT-TTF) 2 IBr 2 [34]. If so, the observed slow oscillations give an excellent opportunity to find the value of t z and of the product k F d at low temperature in tritellurides TbTe 3 and GdTe 3 from the experimental data on the intralayer MR.…”

“…Conductivity, being a non-linear function of the oscillating electronic density of states (DoS) and of the diffusion coefficient, has slow oscillations with frequency 2 ∆F , while magnetization, being a linear functional of DoS, does not show slow oscillations [34,39]. The slow oscillations have many interesting and useful features as compared to the fast quantum oscillations.…”

“…At t z ∼ ω c new qualitative features appear both in the monotonic and oscillating parts of MR. For example, the strong monotonic growth of interlayer MR R zz (B z ) was observed in various Q2D metals [26][27][28][29][30][31][32][33][34][35] and recently theoretically explained [35][36][37][38]. The oscillating part of interlayer MR at µ ≫ t z ω c acquires the slow oscillations [34,39] and the phase shift of beats. [39,40] These two effects are missed by the standard 3D theory [16][17][18] because they appear in the higher orders in ω c /t z .…”

Magnetic quantum oscillations in the charge-density-wave state of the organic metals α-(BEDT-TTF)2MHg(SCN)4 with M = K and Tl

“…(3) of Ref. [65] and the oscillations of ρ 2D (E F ) = 1/τ i (E F ) are given by the Eq. (2) of Ref.…”