  The layered transition metal dichalcogenides host a rich collection of charge
density wave (CDW) phases in which both the conduction electrons and the atomic
structure display translational symmetry breaking. Manipulating these complex
states by purely electronic methods has been a long-sought scientific and
technological goal. Here, we show how this can be achieved in 1T-TaS2 in the
two-dimensional (2D) limit. We first demonstrate that the intrinsic properties
of atomically-thin flakes are preserved by encapsulation with hexagonal boron
nitride in inert atmosphere. We use this facile assembly method together with
TEM and transport measurements to probe the nature of the 2D state and show
that its conductance is dominated by discommensurations. The discommensuration
structure can be precisely tuned in few-layer samples by an in-plane electric
current, allowing continuous electrical control over the
discommensuration-melting transition in 2D.
