We investigate electron transport along the surface of WTe₂ three-dimensional single crystals, which are characterized by the coexistence of Weyl semimetal conductivity and ferroelectricity at room temperature. We find that non-linear behavior of dV/dI(I) WTe₂ differential resistance is accompanied by slow relaxation process, which appears as the dV/dI(I) dependence on the sign of the current change. This observation is confirmed by direct investigation of time-dependent relaxation curves. While strongly non-linear differential resistance should be expected for the zero-gap WTe₂, the slow relaxation in transport is very unusual for well-conducting semimetals at room temperature. We establish, that non-monotonic dependence of the amplitude of the effect on driving current ΔdV/dI(I) well corresponds to the known Sawyer–Tower’s ferroelectric hysteresis loop. The possibility to induce polarization current by source-drain field variation is unique for WTe₂, since it is a direct consequence of the coexistence of ferroelectricity and metallic conduction. This conclusion is also confirmed by gate voltage dependencies, so our results can be understood as a direct demonstration of WTe₂ ferroelectric behavior in charge transport experiment.

我们研究了沿WTe ₂三维单晶表面的电子传输，其特征是室温下Weyl半金属电导率和铁电共存。我们发现dV / dI（I）WTe ₂差动电阻的非线性行为伴随着缓慢的松弛过程，这表现为dV / dI（I）对电流变化符号的依赖性。通过直接研究随时间变化的弛豫曲线可以证实这一观察结果。虽然零间隙WTe ₂应该具有强烈的非线性差分电阻，对于室温下导电良好的半金属，运输中的缓慢弛豫是非常不寻常的。我们确定，影响幅度对驱动电流ΔdV / dI（I）的非单调性很好地对应于已知的Sawyer-Tower铁电磁滞回线。对于WTe _2而言，通过源极-漏极场变化感应极化电流的可能性是独特的，因为这是铁电和金属导电共存的直接结果。栅极电压依赖性也证实了这一结论，因此我们的结果可以理解为电荷传输实验中WTe ₂铁电行为的直接证明。