  In crystals, the duplication of atoms often follows different periodicity
along different directions. It thus gives rise to the so called anisotropy,
which is usually even more pronounced in two dimensional (2D) materials due to
the absence of $\textbf{z}$ dimension. Indeed, in the emerging 2D materials,
electrical anisotropy has been one of the focuses in recent experimental
efforts. However, key understandings of the in-plane anisotropic resistance in
low-symmetry 2D materials, as well as demonstrations of model devices taking
advantage of it, have proven difficult. Here, we show that, in few-layered
semiconducting GaTe, electrical conductivity along $\textbf{x}$ and
$\textbf{y}$ directions of the 2D crystal can be gate tuned from a ratio of
less than one order to as large as 10$^{3}$. This effect is further
demonstrated to yield an anisotropic memory resistor behaviour in ultra-thin
GaTe, when equipped with an architecture of van der Waals floating gate. Our
findings of gate tunable giant anisotropic resistance (GAR) effect pave the way
for potential applications in nano-electronics such as multifunctional
directional memories in the 2D limit.
