Coherent Manipulation of Individual Electron Spin in a Double Quantum Dot Integrated with a Micro-Magnet

TL;DR

This paper demonstrates the coherent control of individual electron spins in a double quantum dot system integrated with a micro-magnet, using electric dipole spin resonance to achieve precise manipulation of spin states.

Contribution

It introduces a novel experimental setup combining a micro-magnet with a double quantum dot for coherent spin manipulation, and provides detailed analysis of Rabi oscillations and local magnetic field effects.

Findings

Observation of two resonant CW peaks and Rabi oscillations at different magnetic fields.

Validation of the quadratic relationship between CW current and MW voltage.

Measurement of Rabi frequencies reflecting MW electric field differences across dots.

Abstract

We report the coherent manipulation of electron spins in a double quantum dot integrated with a micro-magnet. We performed electric dipole spin resonance experiments in the continuous wave (CW) and pump-and-probe modes. We observed two resonant CW peaks and two Rabi oscillations of the quantum dot current by sweeping an external magnetic field at a fixed frequency. Two peaks and oscillations are measured at different resonant magnetic field, which reflects the fact that the local magnetic fields at each quantum dot are modulated by the stray field of a micro-magnet. As predicted with a density matrix approach, the CW current is quadratic with respect to microwave (MW) voltage while the Rabi frequency (\nu_Rabi) is linear. The difference between the \nu_Rabi values of two Rabi oscillations directly reflects the MW electric field across the two dots. These results show that the spins on each dot can be manipulated coherently at will by tuning the micro-magnet alignment and MW electric field.