Quantum Dipole Effects in a Silicon Transistor under High Electric Fields

Strongly correlated one-dimensional systems are paradigms for theoretical condensed-matter physics, since various predictions such as spin–charge separation and topological phase transitions can be determined based on mathematically rigid models. Some of these features were experimentally observed in carbon nanotubes and chiral edge states of quantum Hall systems. Here, we show the emergence of another one-dimensional system in a nanoscale silicon field-effect-transistor with a wide and short hole channel when a strong electric field is applied at low temperatures. We observed the quantum dipoles, which form at the ultra-thin gate interface and exhibit a phase transition, and the drain current showed a clear, negative differential conductance due to the screening of electric fields by antiferroelectric ordering. We have also found new current plateaus against drain voltages, which corresponds to the magnetisation plateau theoretically predicted by the one-dimensional spin model. We obtained phase diagrams of the field-induced phase transitions by gate-induced doping.