Quantum-enabled Enhancements in presence of Noise (QueEN)

The written word is one of the greatest inventions of the human mind. From clay tablets, through papyrus, paper, punch-cards, onto the magnetic hard-disks of computers, each has represented a revolutionary method of recording information -- a transformation in human civilisation. Allied to each of these, the ways of processing and transferring information have undergone dramatic changes. The latest in this line of change and innovation is our digital information age. This phenomenal advance it is not the culmination of our endeavours, and yet greater advances can be achieved by harnessing the idea that information is not an ephemeral notion, but an integral part of physical reality.

The best known theory describing physical reality is quantum physics, and this promises to be the next disruptive transformation in the process of recording, processing, transferring and even acquiring information. Quantum information science (QIS) has already demonstrated, in proof-of-principle experiments, the promise of super-efficient computation, unconditionally secure communication, super-precise measurements, and much more. These enhanced capabilities rely on the existence of quantum entanglement. Unfortunately, the laws of physics that underlie entanglement also make it extremely fragile and vulnerable. And this chasm divides the principle and practice of QIS.

My research will bridge this gap - by designing quantum protocols that rely on resilient forms of quantum correlations, using them to develop quantum enhanced measurement and communication protocols. To learn more about the resilience of nonclassical correlations, I will study their evolution in the noisiest of environments - a biological molecule. It will inform our ability to manipulate and maintain nonclassical correlations in noisy environments, and allow us to study the role of quantum mechanics in biological processes.

Robustness and scalability will be a central aspect in the design of the protocols developed in this project, and I will work closely with experimentalists to bring these advantages to the real world. I will concentrate on two particular applications. The first of these is quantum-enhanced precision measurements. It is known that quantum mechanics can measure single parameters with precisions impossible classically. Measuring several parameters simultaneously is however a very sophisticated problem, and forms the basis of sophisticated applications such as the development of microscopes and cameras. Not much is known about the quantum theory of measuring multiple parameters simultaneously, and my project will develop this mathematical theory. This will be followed by experiments demonstrating the quantum advantages promised by the theoretical developments - first in laboratory settings, and then in-situ biological samples.

My second objective is to develop quantum communication protocols relying resilient quantum correlations that are less fragile than quantum entanglement. I will begin by developing the theoretical principles underpinning recently identified forms of robust, nonclassical correlations such as quantum discord, which can provide quantum enhanced performance. This will enable the optimal manipulation of these correlations to deliver quantum advantages in the real world.

Finally, I will study nonclassical correlations in a very noisy biological system called a light-harvesting complex, a molecule transferring solar energy absorbed by photosynthetic organisms to a chemical reaction centre, being ~ 99% efficient. Clearer understanding of this process could have immense ramifications in developing artificial systems that can harness solar energy better than our best solar cells, which only operate at ~ 30% efficiency. Beyond this major technological and correspondingly societal change, my research will explore the intriguing question of whether quantum mechanical effects are directly used to confer selective advantage in life processes.

Real world quantum-enabled technologies hold immense promise for the future. Even if it forms a mere 1% of just the UK manufacturing sector, it will be an industry worth more than a billion pounds annually. The key to unlocking this potential lies in the realisation of palpable quantum advantages in the presence of losses and imperfections -- predicated upon the identification of resources that provide quantum advantages in the presence of noise, and then designing protocols that harness these resources. This understanding will underpin developments in quantum communication, computation, sensing, imaging, and computing and beyond. Therefore, a prompt direction of efforts to the realisation of tangible quantum enhancements in the non-ideal environment of our day-to-day lives could return large dividends on scientific, practical and economic fronts.

The proposed project will develop a theoretical framework for achieving tangible quantum enhancements in the real world by going beyond the proof-of-principle experiments that observed some quantum advantages but overlooked the fundamental demand for scalability. Thus, the key road-block to the realization of the potential of quantum technologies is practicality, a shortcoming to be addressed in this project. This could underpin a technological revolution which will have a transformative impact on our ever more information-based society, both economically and in changing the way we live and connect.

The key first-stage beneficiaries will be those in academia, but this will have some indirect non-academic benefits. For example, surpassing the best known classical bounds in multi-parameter quantum metrology in the presence of losses and imperfections will lead to the development of quantum imaging. Addressing this issue is a central aim of my research and my publications will stimulate cross-disciplinary approaches involving biochemistry and medical physics. This will build momentum towards realising a real-world quantum imaging system, with important impacts outside the academic community in the health and biomedical sector. In the health sector, quantum imaging could provide novel diagnostic methods for malignant conditions in a decade's time.

The second-stage beneficiaries include non-academic industrial and commercial sectors, and indeed society as a whole. For instance, quantum simulations would transform methods of research and commercialization in the health, pharmaceuticals and green energy sectors. It could assist epidemiology and genetic research, cut costs in drug design, and improves artificial light-harvesting devices by permitting simulations of efficient photosynthesis. Indeed, this will have an impact in any area requiring innovation at the molecular scale, where classical computers are ineffectual and time-consuming, and where expensive empirical testing is currently the only option. Over a scale of 10-20 years, these endeavours should lead to the creation and growth of companies and jobs; enhancing business revenue and the UK's innovative capacity.

There are already known quantum computation algorithms operating on highly mixed states that have little or no entanglement, and yet provide exponential advantages over the best classical algorithms. Quantum discord is the resource for such enhancement. My early breakthroughs and continued contribution to this program places me in a prime position to capitalize on this understanding, leading to robust, scalable protocols with intellectual property and industrial development possibilities. In the long term, the commercialisation and exploitation of scientific knowledge could lead to spin out companies, and the creation of new processes, products and services.