Quantum Phenomenology and Quantum Technology

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Quantum physics arrived in the twentieth century and challenged the foundations of science by introducing a fundamental indeterminacy in nature and rejecting local realism. In the same century quantum physics ushered in new technologies such as nuclear power, transistors and lasers. Recently new exciting quantum proposals emerged including quantum computing, quantum cryptography, quantum metrology, quantum states of matter and quantum transport in biomolecular complexes. My research programme focuses on four exciting aspects of quantum science chosen strategically to push forward the state of the art in quantum science and technology. Quantum computing’s goal is to convert certain intractable computational problems into easy-to-solve problems on quantum computers. The earliest computations that answer questions beyond the reach of classical computers is likely to be quantum simulation, which will mimic evolution of quantum systems and could have wide applications for example to solving linear equations. I will develop quantum algorithms for measurement that take the current state-generation approach of quantum simulation to full problem-solving, and I will develop quantum algorithms for simulating relativistic and open quantum systems. My aim is to construct quantum algorithms for small-scale quantum computers to solve otherwise-intractable problems. One challenge to realizing quantum information processing is that practically realizable operations do not quite meet the needs of quantum information processing, but quantum control aims to implement sequential realistic operations, in some cases with feedback, to realize necessary operations. I tractable autonomous algorithms for designing control sequences for constrained quantum control, for example tightly limiting the execution time. Greedy algorithms are popular and fast but require local optima to be good enough, which can fail for constrained problems. I plan to adapt our non-greedy artificial-intelligence quantum-metrology algorithms to find good quantum-control algorithms with the benefit of finding control sequences that are both fast and accurate. Advances in quantum science depend crucially on experimental advances so I will work on experimental proposals and collaborations aiming to advance the state of the art. My focus over the next few years is on three media: interferometry with single-photon inputs, superconducting-circuits with artificial atoms and silicon-surface dangling bonds. My interferometry work aims to perform BosonSampling efficiently. BosonSampling is expected to be efficient with interferometers but intractable using classical computation. I am working on controlling and observing collective effects for artificial atoms in superconducting circuits, and I aim to using collective and coherent effects in these artificial atoms to control microwave pulses with applications to scalable quantum computing. The silicon-surface double dangling bond project explores and ultimately exploits quantum coherent dynamics of electron tunneling between dangling bonds. In the past few years quantum effects in biological systems such as coherent exciton transport in photosynthesis has been a hot topic. Inspired by the prospect of coherent transport and by the capability of studying electron transfer between proteins for native and mutant species, we showed that the solvent plays an active role in electron transfer, but the exact role of the solvent in assisting electron transfer is not established. Our aim now is to determine the role of the solvent and compare our results with existing and planned experiments. As efficient site-selective electron transfer is vital for metabolism, our research on electron transfer is likely to provide insight into health issues.