Analytic view on coupled single-electron lines

Abstract

The fundamental properties of two electrostatically interacting single-electron lines (SEL) are determined from a minimalistic tight-binding model. The lines are represented by a chain of coupled quantum wells that can be implemented in a mainstream nanoscale CMOS process technology and tuned electrostatically by DC or AC voltage biases. The obtained results show an essential qualitative difference with two capacitively coupled classical electrical lines. The derived equations and their solutions prove that the two coupled SET lines can create an entanglement between electrons. The correlation function characterizing the correlation/anticorrelation in electron position is introduced both in quantum and classical descriptions of capacitively coupled SELs. The quantum measurement conducted on quantum and classical SELs is described. The difference in quantum and classical ground states can be used as the probe determining the 'quantumness' of the SEL system. The results indicate a possibility of constructing electrostatic (non-spin) coupled qubits that could be used as a building block in a CMOS quantum computer.