  Voltage-driven 180$^\circ$ magnetization switching without electric current
provides the possibility for revolutionizing the spintronics. We demonstrated
the voltage-driven charge-mediated 180$^\circ$ magnetization switching at room
temperature by combining first-principles calculations and
temperature-dependent magnetization dynamics simulation. The electric field
($E$) induced interface charge is found to allow a giant modulation of the
magnetic anisotropy ($K$) of the nanomagnet. Particularly $K$ is revealed to
vary linearly with respect to $E$ and the epitaxial strain. Magnetization
dynamics simulations using the so-obtained $K$ show that both in-plane and
perpendicular 180$^\circ$ switching can be achieved by $E$ pulses. The
temperature effect renders the 180$^\circ$ switching as probability events.
Statistical analysis indicates a fast (around 4 ns) and low-error-probability
180$^\circ$ switching achievable at room temperature by controlling the
magnitude of $E$ and the pulse width. The study inspires the rational design of
miniaturized nanoscale spintronic devices where thermal fluctuation has a great
impact.
