Ultrafast control of donor-bound electron spins with single detuned optical pulses

TL;DR

This paper demonstrates ultrafast control of donor-bound electron spins in semiconductors using single detuned optical pulses, achieving rapid spin rotations with potential applications in quantum information processing.

Contribution

It introduces and experimentally validates a robust optical technique for coherent spin manipulation using single broadband pulses detuned from resonance.

Findings

Demonstrated donor-bound electron spin rotations exceeding pi/4 with single pulses

Achieved two-pulse areas exceeding pi/2 for spin control

Technique is robust and potentially scalable to larger pulse areas

Abstract

The ability to control spins in semiconductors is important in a variety of fields including spintronics and quantum information processing. Due to the potentially fast dephasing times of spins in the solid state [1-3], spin control operating on the picosecond or faster timescale may be necessary. Such speeds, which are not possible to attain with standard electron spin resonance (ESR) techniques based on microwave sources, can be attained with broadband optical pulses. One promising ultrafast technique utilizes single broadband pulses detuned from resonance in a three-level Lambda system [4]. This attractive technique is robust against optical pulse imperfections and does not require a fixed optical reference phase. Here we demonstrate the principle of coherent manipulation of spins theoretically and experimentally. Using this technique, donor-bound electron spin rotations with single-pulse areas exceeding pi/4 and two-pulses areas exceeding pi/2 are demonstrated. We believe the maximum pulse areas attained do not reflect a fundamental limit of the technique and larger pulse areas could be achieved in other material systems. This technique has applications from basic solid-state ESR spectroscopy to arbitrary single-qubit rotations [4, 5] and bang-bang control[6] for quantum computation.