Spin Charging Sequences in Three Colinear Laterally Coupled Vertical Quantum Dots

Abstract

As the size of electronic device dimensions decreases, quantum effects become more prominent and interfere with conventional device operation. In quantum computing, the basic unit of information is a quantum bit or qubit, which can be represented by a superposition of two unit vectors in the two-dimensional (2D) Hilbert space. Coupled quantum dots are promising systems for realizing CNOT gates and moreover, entanglement between two electron spin qubits can be manipulated by external electric and magnetic fields. This chapter describes theoretically the few-electron properties of three laterally coupled vertical quantum dots. It offers the advantage of the modulation of the interdot coupling potential with tuning gates, and the control of electron confinement within each of the three dots with a separate set of gates. The chapter provides design guidelines for optimizing the structure for operation with realistic sets of voltage values, which for the few-electron regime are often difficult to access experimentally.