Abstract: Magnetic tunnel junction transistor devices and methods for operating and foaming magnetic tunnel junction transistor devices. In one aspect, a magnetic tunnel junction transistor device includes a first source/drain electrode, a second source/drain electrode, a gate electrode, and a magnetic tunnel junction disposed between the gate electrode and the second source/drain electrode. The magnetic tunnel junction includes a magnetic free layer that longitudinally extends between, and is overlapped by, the first and second source/drain electrodes. The gate electrode completely overlaps the magnetic free layer between the first and second source/drain electrodes. The magnetic tunnel junction transistor device switches a magnetization orientation of the magnetic free layer by application of a gate voltage to the gate electrode, thereby changing a resistance between the first and second source/drain electrodes through the magnetic free layer.