CC BY
0COLLECTIVE NATURE OF LOW-TEMPERATURE CONDUCTION, PHOTOCONDUCTION AND CHARGE DENSITY WAVE PINING IN ORTHORHOMBIC
TaS3
Minakova V. E .1, Zaitsev-Zotov S. V.2
1Institute of Radioengineering and Electronics, Moscow, Russia, mina_cplire@mail.ru 4nstitute of Radioengineering and Electronics, Moscow, Russia, SerZZ@cplire.ru
This work summarizes the results of a series of works [1-5] devoted to the study of low-temperature conduction and photoconduction of the Peierls conductor o-TaS3. The tools we used for changing the relationship between the single-particle and collective components of low-temperature conduction and photoconduction in o-TaS3 - illumination and uniaxial stretching of the sample - allowed us to separate the single-particle and collective contributions to these quantities. Based on the analysis of the data obtained, we came to the following conclusions:
1. The nature of the conduction of o-TaS3 at high (100 < T < 220 K) and low (T < 80 K) temperatures is different due to the difference in the nature of the dominant current carriers. In the high-temperature region, conduction is due to single-particle carriers (quasiparticles), and in the low-temperature region, the contribution of collective excitations (solitons) predominates. Illumination allows a significant increase in conduction due to photoconduction arising from nonequilibrium quasiparticles excited by light.
2. The reasons for the change in the nature of photoconduction at high (60 < T < 77 K) and low (T < 45 K) temperatures are similar: it occurs due to a change in the type of the dominant current carriers from single-particle to collective. The collective contribution to low-temperature photoconduction is usually not noticeable but can be significantly enhanced by stretching the sample. The increase in the concentration of nonequilibrium collective carriers (solitons) is caused by the fact that stretching increases the deviation of the CDW wave vector [6] from fourfold commensurability.
3. The charge density wave (CDW) pinning dimensionality (determined by the discovered analogy between the effects of stretching and illumination on the conduction of o-TaS3) also changes dramatically with temperature:
1) As the temperature decreases in the range 40 K < T < 60 K, a transition from three-dimensional (3D) to one-dimensional (1D) CDW pinning is observed for samples that were initially in a state with 3D pinning.
2) At low temperatures T < 40 K, 1D pinning is observed for all samples.
The effect of the decrease in the CDW pinning dimensionality with decreasing temperature is associated with a change in the screening conditions of electric fields arising during CDW deformation due to a change in the type of the main screening current carriers from single-particle to collective carriers.
Литература
1. Zaitsev-Zotov S.V., Minakova V.E. // Pis'ma v ZhETP. - 2004. - V. 79. - C. 550-554.
2. Zaitsev-Zotov S.V., Minakova V.E. // Phys. Rev. Lett. - 2006. - V. 97. - C. 266404-1 -266404-4.
3. Zaitsev-Zotov S.V., Minakova V.E. // J. Phys. IV. - 2005. - V. 131. - C. 95-100.
4. Minakova V.E., Taldenkov A. N., Zaitsev-Zotov S.V.// JETP Letters. - 2019. - V. 110. -C. 200-205.
5. Minakova V.E., Zaitsev-Zotov // Журнал радиоэлектроники. - 2023. - №. 12.
6. Zybtsev S.G., Pokrovskii V.Ya. // Physica B. - 2015. - V. 460. - C. 34 - 38.
