Welcome to the Rydberg Atom Quantum Technologies team lead by Dr. Jonathan Pritchard, an RAEng Senior Research Fellow at the University of Strathclyde.
Overview
Rydberg atoms are atoms excited to extremely large principal quantum numbers resulting in giant atoms offering exaggerated properties including enormous electricdipole moments in the microwave frequency range and strong, tuneable longrange interactions. Our research is focused on developing new quantum technologies that exploit these properties to develop scalable platforms for quantum computation and optimisation, and atomic gas sensors for precision microwave field detection and imaging.
Please contact jonathan.pritchard@strath.ac.uk if you are interested in working in within one of our research areas – we have both PhD and PDRA Positions Currently Available across both projects developing neutral atom quantum computers based on scalable arrays of neutral atoms.
Research
Scalable Qubit Arrays for Quantum Computing and Optimisation (SQuAre) 

This project is an EPSRC Prosperity Partnership with M Squared Lasers that aims to develop a new platform for quantum computing based on scalable arrays of neutral atoms that is able to overcome the challenges to scaling of competing technologies. We will develop new hardware to cool and trap arrays of over 100 qubits that will be used to perform both analogue and digital quantum simulation by exploiting the strong longrange interactions of highly excited Rydberg atoms. Together with the quantum software team lead by Prof. Andrew Daley, we will design new analogue and digital algorithms tailored for the neutralatom platform to target industriallyrelevant computation and optimisation problems.
Team: Jonathan Bass, André Oliveira, Boyko Nikolov, Elliot DiamondHitchcock 

Quantum Error Correction using Cryogenic DualSpecies Arrays 

This project, supported by the Royal Academy of Engineering and M Squared Lasers, seeks to develop a new experiment focused on creating dualspecies arrays of Cs and Rb for error correction. This is integrated within a 4K closedcycle cryostat to obtain extended trap lifetime for scaling to large numbers of qubits, and will focus on exploiting longrange dipole interactions between Rydberg states of each species to enable midcircuit, nondestructive readout and generation of topologically protected logical qubits as a route towards fault tolerant digital quantum computing.
Team: Daniel Walker and Paul Ireland 

Microwave Field Sensing using Rydberg atoms 

RF fields in the microwave and terahertz domain are ubiquitous for security and communications, however test equipment requires frequent recalibration and careful understanding of the perturbations caused by the antenna used for measurement. This project, a collaboration between researchers at the University of Strathclyde and Durham University, seeks to develop new alloptical field sensors operating in the microwave and terahertz domain using Rydberg atoms in a thermal vapour to act as microscopic antenna enabling metalfree probing, subwavelength imaging resolution and the ability to implement a traceable SI calibration offering superior sensitivity compared to existing technologies. Early results include a careful characterisation of linearity and optimal state choice for precision RF sensing using this approach.
Team: Aurélien Chopinaud


Compact Pair Source for Quantum Enhanced LIDAR 

In collaboration with the theory team lead by Prof. John Jeffers and supported by DSTL, we are developing new approaches to quantum enhanced LIDAR by creating a compact optical frequency comb source for pumping birefringent optical fibres and exploring a new loglikelihood metric to perform quantum enhanced standoff detection and rangefinding.
Team: Mateusz Mrozowski


ARC:Alkali Rydberg CalculatorAn opensource python library for calculating properties of Alkali Rydberg atoms developed with Nikola Sibalic, Charles Adams and Kevin Weatherill at JQC in Durham. Full details on the arXiv:1612.05529 – download source from GitHub or use the online Atom Calculator by following the link below. 
Previous Projects
Two qubit quantum gate operations and hybrid systems based on atoms coupled to superconducting circuits 

As part of an EPSRC Quantum Technology Fellowship we developed a new experimental apparatus to perform twoqubit operations using individually trapped Cs atoms. Highlights from this work included first demonstrations of single atom imaging using an sCMOS camera, highfidelity and longcoherence entanglement generation and the first native CNOT gate protocol based on electromagnetically induced transparency. This apparatus has now been rebuilt as part of the Quantum Error Correction using Cryogenic DualSpecies Arrays project which builds on these early milestones and will integrate the system into a 4 K cryostat.
Separately we investigated hybrid approaches to quantum networking by developing optimised NbN resonators at 15 GHz for coupling Rydberg states to superconducting microwave circuits in a 4 K environment in collaboration with the Quantum Devices group at Glasgow University lead by Martin Weides. We have shown theoretically that this system can be used for demonstrations of strongcoupling and active cooling providing Q factors of 10^{5} and above can be achieved. 
Group Publications
 B. Nikolov, E. DiamondHitchcock, J. Bass, N.L.R Spong and J.D. Pritchard, Randomized Benchmarking using NonDestructive Readout in a 2D Atom Array, arXiv:2301.10510 (2023)
 M. Mrozowski, J.Jeffers and J.D. Pritchard, Highefficiency coupledcavity optical frequency comb generation, Optics Continuum 2, 894 (2023) [arXiv]
 K. McDonnelI, L.F. Keary and J.D. Pritchard, Demonstration of a Quantum Gate using Electromagnetically Induced Transparency, Phys. Rev. Lett. 129, 200501 (2022)[arXiv]
 G. Pelegri, A. Daley and J.D. Pritchard, Highfidelity multiqubit Rydberg gates via twophoton adiabatic rapid passage, Quantum Sci. Technol. 7, 045020 (2022)
 L.F. Keary and J.D. Pritchard, Strong coupling and active cooling in a finitetemperature hybrid atomcavity system, Phys. Rev. A 105, 013707 (2022)
 M. Mrozowski, J.Jeffers and J.D. Pritchard, A practical compact source of heralded single photons for simple detection LIDAR, Proc. SPIE 11835, Quantum Communications and Quantum Imaging XIX, 1183508 (2021)
 A. Chopinaud and J.D. Pritchard, Optimal State Choice for Rydberg Atom Microwave Sensors, Phys. Rev. Appl. 16, 024008 (2021)
 Y. Chu, J.D. Pritchard, H. Wang, and Martin Weides,Hybrid quantum devices: Guest editorial, Appl. Phys. Lett. 118, 240401 (2021)
 C.S. Adams, J.D. Pritchard and J. Shaffer, Rydberg atom quantum technologies, J. Phys. B 53 012002 (2020) [arXiv]
 C.J. Picken, R. Legaie, K. McDonnell and J.D. Pritchard, Entanglement of neutralatom qubits with long groundRydberg coherence times, Quantum Sci. Technol. 4, 015011 (2018) [arXiv]
 R. Legaie, C.J. Picken and J.D. Pritchard, SubkHz excitation lasers for Quantum Information Processing with Rydberg atoms, J. Opt. Soc. B 35, 892 (2018) [arXiv]
 C.J. Picken, R. Legaie and J.D. Pritchard, Single atom imaging with an sCMOS camera, Applied Physics Letters 111, 164102 (2017) [arXiv]
 N. Šibalić, J.D. Pritchard, C.S. Adams and K.J. Weatherill, ARC: An opensource library for calculating properties of alkali Rydberg atoms, Computer Physics Communications 220, 319 (2017). See atomcalc.jqc.org.uk.
Funding
We acknowledge funding from the following sources:
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