Silicon Quantum Dots with Counted Antimony Donor Implants

TL;DR

This paper demonstrates precise implantation and counting of antimony donors near silicon quantum dots using a focused ion beam and integrated ion detectors, enabling controlled donor placement for quantum computing.

Contribution

It introduces a method for deterministic donor implantation and counting with single-ion precision in silicon quantum dot devices.

Findings

Single-ion donor counting achieved

Coulomb blockade observed in quantum dots

Charge offsets indicate donor ionization

Abstract

Deterministic control over the location and number of donors is crucial to donor spin quantum bits (qubits) in semiconductor based quantum computing. In this work, a focused ion beam is used to implant antimony donors close to quantum dots. Ion detectors are integrated next to the quantum dots to sense the implants. The numbers of donors implanted can be counted to a precision of a single ion. In low-temperature transport measurements, regular coulomb blockade is observed from the quantum dots. Charge offsets indicative of donor ionization are also observed in devices with counted donor implants.