Chiral Unitary Quantum Phase Transition in 2 H-Fe_xTaSe_2
Abstract
We have observed a metal-insulator transition of a quasi-two-dimensional electronic system in transition metal dichalcogenide 2 H-TaSe_2 caused by doping iron. The sheet resistance of 2 H-Fe_xTaSe_2 (0 ≤ x ≤ 0.120) single crystals rises about 10^6 times with the increasing of x at the lowest temperature. We investigated the temperature dependence of the resistance and found a metal-insulator transition with a critical sheet resistance 11.7 ± 5.4 k{Ω }. The critical exponent of the localization length ν is estimated 0.31 ± 0.18. The values of the critical sheet resistance and ν are accordant to those of the chiral unitary class (less than h/1.49e^2=17.3 k{Ω } and 0.35 ± 0.03, respectively). We suggest that 2 H-Fe_xTaSe_2 is classified as the chiral unitary class, not as standard unitary class.
- Publication:
-
Journal of Low Temperature Physics
- Pub Date:
- April 2016
- DOI:
- 10.1007/s10909-016-1502-3
- arXiv:
- arXiv:1603.04175
- Bibcode:
- 2016JLTP..183...41K
- Keywords:
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- Conductivity of disordered solids;
- Conductivity of transition metal compounds;
- Quantum phase transition;
- Anderson localization;
- Condensed Matter - Mesoscale and Nanoscale Physics;
- Condensed Matter - Strongly Correlated Electrons
- E-Print:
- 10 pages, 4 figures