Thermal transport studies on charge density wave materials LaPt₂Si₂ and PrPt₂Si₂

Abstract

We measured the thermal properties of polycrystalline samples of LaPt2Si2 and PrPt2Si2 using thermopower (S) along with thermal conductivity (κ) in the temperature range 10 K–300 K. Significant anomalies related to charge density waves (CDW) around 112 K and 88 K respectively have been observed in in both systems. Analysis of thermopower by a two band model suggests that the observations are consistent with a reduction of electron charge density. A change in slope accompanied by a drop in the value of thermal conductivity has been observed around TCDW in case of LaPt2Si2. Analysis of thermal conductivity of this material suggests that the CDW mainly affects electronic contribution to thermal transport. Only a slight change of slope has been detected in temperature dependent thermal conductivity in the case of PrPt2Si2 around TCDW, while its resistivity shows a clear anomaly which shows that electronic part of thermal conductivity is mainly influenced by the CDW in this case also. It is interesting to note that the lattice contribution to thermal conductivity remains unaffected by the CDWs in both materials.

Nodeless superconductivity in the charge density wave superconductor LaPt$_2$Si$_2$

“…indicated by the pronounced hysteresis loop. The transition temperature in our data is a little lower than that reported for the polycrystalline samples [16,29]. The inset of Fig.…”

Evolution of charge density wave order and superconductivity under pressure in LaPt2Si2

“…Additional superlattice reflections corresponding to the tripling of the unit cell along the [110] direction [20] strongly suggests the presence of CDW order. Furthermore, CDW order is detected in arXiv:2004.03111v1 [cond-mat.supr-con] 7 Apr 2020 other physical quantities such as the thermopower and thermal conductivity [22]. First principles calculations suggest that the Fermi surface of LaPt 2 Si 2 is quasi twodimensional, and that there is coexistence of CDW order and SC in the [Si2-Pt1-Si2] layer [23,24].…”

A brief review of the physical properties of charge density wave superconductor LaPt2Si2

“…Figures 3(a) and (b) present the temperature-variation of electrical resistivity ρ(T) measured on single crystalline LaPt 2 Si 2 for current density applied along a-and c-axes as reported in [53]. It would be worthwhile to mention that the CDW transition in the single crystal occurs at a significantly lower temperature 85 K, compared to 112 K in the polycrystalline LaPt 2 Si 2 , as confirmed by various groups [51,52,79].…”

“…Thermals transport results were reported in [53]. Figures 4(b) and (c) summarize the results of thermal transport measurements including temperature-dependent thermopower S(T) and thermal conductivity κ(T) performed on a polycrystalline LaPt 2 Si 2 .…”