Fig. 2: BKT behaviour in FeSe thin flakes.
From: Suppression of superconductivity and enhanced critical field anisotropy in thin flakes of FeSe
a, b Voltage-current (IV) curves for 100 nm and 14 nm FeSe devices at different temperatures in the vicinity of Tc. The solid black lines are linear fits to the low current regime used to extract the exponent α from the V ∝ Iα(T) dependence. c, d Plot of the exponent α extracted from a, b) (left axis) and the resistance transition (right axis) as a function of temperature. α(T) reaches a value of 3 at TBKT = 6.67 K for the 100 nm and TBKT = 2.9 K for 14 nm device. The location of TBKT is indicated by an arrow.
