Tunable Positive to Negative Magnetoresistance in Atomically Thin WTe₂

Abstract

Transitional metal ditelluride WTe has been extensively studied owing to its intriguing physical properties like nonsaturating positive magnetoresistance and being possibly a type-II Weyl semimetal. While surging research activities were devoted to the understanding of its bulk properties, it remains a substantial challenge to explore the pristine physics in atomically thin WTe. Here, we report a successful synthesis of mono- to few-layer WTe via chemical vapor deposition. Using atomically thin WTe nanosheets, we discover a previously inaccessible ambipolar behavior that enables the tunability of magnetoconductance of few-layer WTe from weak antilocalization to weak localization, revealing a strong electrical field modulation of the spin-orbit interaction under perpendicular magnetic field. These appealing physical properties unveiled in this study clearly identify WTe as a promising platform for exotic electronic and spintronic device applications.

The study on quantum material WTe2

“…Lv et al [69] also observed the significant anisotropic Adler-Bell-Jackiw (ABJ) anomaly and possible temperature-induced topological phase transition in the Fermi-level delicately adjusted WTe 1.98 crystals. Similar negative magnetoresistance effect has also been observed in WTe 2 nanosheets synthesized by chemical vapour deposition technique [70]. However, this negative magnetoresistance effect hasn't been found in its sister compound MoTe 2 till now.…”

Observation of Shubnikov-de Haas Oscillations in Large-Scale Weyl Semimetal WTe2 Films*

“…The RRR of WTe2 film annealed for 96 hours is unexpectedly smaller than others, suggesting that the long annealing time may cause the existence of the much more content of Te vacancies in the WTe2 films. [23,34] The MR curves (MR = ( ) × 100%) are shown in Fig. 2(b To clarify the transport properties of the WTe2 film annealed for 72 hours, the dependence of the MR up to 14 T on temperature (from 1.7 to 100 K) is shown in Fig.…”

Atomic Insights into Phase Evolution in Ternary Transition‐Metal Dichalcogenides Nanostructures

“…Through controllable conversion from 2H to the other semimetallic phases Tʹ (monoclinic, Figure b) and T d (orthorhombic, Figure c), the semiconducting to metallic transition can be realized, which helps achieve ohmic contact in heterojunctions and make broad applications including memory and phase‐change devices . Furthermore, many exotic phenomena have been demonstrated in Tʹ and T d crystals, such as large magnetoresistance, quantum spin Hall effect, and superconductivity . Under special growth control, such as laser irradiation, strain engineering and quenching (<250 K), Tʹ transits to T d with inversion‐symmetry breaking (Figure c), from which a new type‐II Weyl semimetal state can be accessed .…”