Low power, fast and broadband ESR quantum control using a stripline resonator

TL;DR

This paper demonstrates low-power, broadband electron spin resonance (ESR) control using a stripline resonator, implementing composite pulses and frequency combs for efficient quantum control of multiple spins.

Contribution

It introduces a broadband BB1 composite pulse and a microwave frequency comb for ESR, effective on samples with broad linewidths and suitable for scalable quantum systems.

Findings

BB1 pulse effective at 38.46 MHz Rabi frequency on 9.35 MHz linewidth sample

Microwave frequency comb enables simultaneous excitation of multiple spin packets

Low microwave power control suitable for electron spin qubits at 0.6 T

Abstract

Using a home-built Ku band ESR spectrometer equipped with an arbitrary waveform generator and a stripline resonator, we implement two types of pulses that would benefit quantum computers: BB1 composite pulse and a microwave frequency comb. Broadband type 1 (BB1) composite pulse is commonly used to combat systematic errors but previous experiments were carried out only on extremely narrow linewidth samples. Using a sample with a linewidth of 9.35 MHz, we demonstrate that BB1 composite pulse is still effective against pulse length errors at a Rabi frequency of 38.46 MHz. The fast control is realized with low microwave power which is required for initialization of electron spin qubits at 0.6 T. We also digitally design and implement a microwave frequency comb to excite multiple spin packets of a different sample. Using this pulse, we demonstrate coherent and well resolved excitations spanning over the entire spectrum of the sample (ranging from -20 to 20 MHz). In anticipation of scaling up to a system with large number of qubits, this approach provides an efficient technique to selectively and simultaneously control multiple qubits defined in the frequency-domain.