Minimal resource to design spin-based quantum transistors

Designing quantum analogous of classical computers components is the heart of quantum information processors. In this sense, for quantum devices, quantum transistors are believed to be as necessary as the classical ones for classical devices. In this paper we design the smallest spin-based quantum transistor. In fact, while previous schemes explore entangled quantum state for simulating the performance of quantum transistors gate (open and close it), in this paper we show that such task can be achieved by a controllable external magnetic field in a three-spin quantum system. Thus, we could reduce the number of physical spins required to design the quantum transistor, since the gate in our transistor is composed by a single-spin, instead two-spin systems. To analyze the performance of our quantum transistor, we consider its robustness against two decohering environments.