One-dimensional subband effects in the conductance of multiple quantum wires in Si metal-oxide-semiconductor field-effect transistors

The electrical transport in narrow (60–80 nm), parallel multiple quantum wires in Si metal-oxide-semiconductor field-effect transistors (MOSFET’s) has been studied at 0.2 K as a function of gate voltage in zero magnetic field and in fields up to 20 T. The conductance of the multiple wires as a function of gate voltage shows well-resolved structures due to successive population of one-dimensional subbands. In addition, quantum oscillations in the gate-voltage derivative of the conductance as a function of magnetic field show, for the first time in a Si MOSFET, characteristics due to magnetic depopulation of one-dimensional subbands.