Designs for a two-dimensional Si quantum dot array with spin qubit addressability

Abstract

Electron spins in Si are an attractive platform for quantum computation, backed with their scalability and fast, high-fidelity quantum logic gates. Despite the importance of two-dimensional integration with efficient connectivity between qubits for medium- to large-scale quantum computation, however, a practical device design that guarantees qubit addressability is yet to be seen. Here, we propose a practical 3 × 3 quantum dot device design and a larger-scale design as a longer-term target. The design goal is to realize qubit connectivity to the four nearest neighbors while ensuring addressability. We show that a 3 × 3 quantum dot array can execute four-qubit Grover’s algorithm more efficiently than the one-dimensional counterpart. To scale up the two-dimensional array beyond 3 × 3, we propose a novel structure with ferromagnetic gate electrodes. Our results showcase the possibility of medium-sized quantum processors in Si with fast quantum logic gates and long coherence times.

Quantum Computing: Fundamentals, Implementations and Applications

“…As far as the physical realization of qubits is concerned spin is envisioned as the promising candidate [32]. Spin-a fundamental property like charge or mass, is associated with subatomic particles like protons, electrons and neutrons.…”

Formation of one-dimensionally self-aligned Si-QDs and their local electron discharging properties

“…The ability to arrange self-assembling formation of Siquantum-dots (QDs) on SiO 2 into arbitrary arrays or patterns is crucial for applications in functional nanodevices: singleelectron (or hole) transistors, [1][2][3][4][5] quantum computations, [6][7][8][9][10][11][12][13] optoelectronics, [14][15][16][17][18] and information storages. [19][20][21][22][23][24] So far, many approaches exist to the ordered spatial arrangement of Si-based QDs.…”

Single-electron pump in a quantum dot array for silicon quantum computers

“…[8][9][10][11] Toward large-scale integrated silicon quantum computers, methods of constructing two-dimensional QD arrays have been theoretically investigated to reduce the enormous number of wires. [12][13][14][15][16][17][18] Several experimental attempts are also underway to develop feasible two-dimensional QD arrays. [19][20][21][22][23] We previously developed two-dimensional large-scale QD arrays with CMOS circuits and demonstrated that each QD could be selectively operated within the array.…”