  The sizes of commercial transistors are of nanometer order, and there have
already been many proposals of spin qubits using conventional complementary
metal oxide semiconductor (CMOS) transistors. However, the previously proposed
spin qubits require many wires to control a small number of qubits. This causes
a significant 'jungle of wires' problem when the qubits are integrated into a
chip. Herein, to reduce the complicated wiring, we theoretically consider spin
qubits embedded into fin field-effect transistor (FinFET) devices such that the
spin qubits share the common gate electrode of the FinFET. The interactions
between qubits occur via the Ruderman Kittel Kasuya Yosida (RKKY) interaction
via the channel of the FinFET. The compensation for the compact implementation
requires high-density current lines in a small space. The possibility of a
quantum annealing machine is discussed in addition to the quantum computers of
the current proposals.

Quantum Physics;Strongly Correlated Electrons