c -axis electrical transport at the metamagnetic transition in the heavy-fermion superconductor UTe2 under pressure

The electrical resistivity of the unconventional superconductor UTe₂ shows very anisotropic behavior in the normal state depending on the current direction. In this paper we show that the maximum in the resistivity ρc for current applied along the c axis at T_ρcᵐᵃˣ≈14.75 K follows the minimum in the thermal expansion T_α★ along the b axis. Under a magnetic field applied along the b axis, T_ρcᵐᵃˣ can be tracked up to the critical point of the first-order metamagnetic transition, which is located near 6 K and 34.5 T. Surprisingly, at the metamagnetic field Hₘ the resistivity ρc shows a steplike decrease while the resistivities ρₐ and ρb, for current along the a and b axes, respectively, show a steplike increase. Under hydrostatic pressure T_ρcᵐᵃˣ and Hₘ decrease significantly up to the critical pressure pc at which superconductivity is suppressed and a long-range antiferromagnetic order appears. We show that the phase diagram at different pressures can be scaled by T_ρcᵐᵃˣ in field and temperature, suggesting that this temperature scale is governing the main interactions in the normal state.