Final Report Summary - QUANTUM DEMS (QUANTUM DYNAMICS AND ENTANGLEMENT IN COMPLEX MANY-BODY SYSTEMS)
During the project period, we have been following the work lines present in the proposal to achieve the main research and training projectives of our project. The work progress and the main achievements are summarized as followed:
(1) To study many-body physics for quantum information processing, we have proposed a new platform for quantum simulation allowing us to study the intriguing coherent phases of many-body physics. We proposed new solid-state architecture for a large-scale quantum simulator based on engineered spin arrays in diamond. As compared with the other physical systems, it can operate at room temperature, and does not require stringent experiment conditions. With extensive Quantum Monte Carlo simulations, we showed that the system could be engineered to simulate a wide variety of interesting strongly correlated models with long-range dipole-dipole interactions that exhibit exotic quantum phases, such as frustrated magnetism and supersolid. This work was published in Nature Physics 9, 168–173 2013.
Such a novel physical system offers a number of opportunities for further study intriguing many-body physics of quasi three-dimensional quantum systems. In fact, it also provides probabilities to construct a scalable measurement-based quantum processor building on ground states of strongly correlated systems, which will in the meantime help to understand the properties of many-body quantum systems from the perspective of quantum computation. The rapid progress of experiments with color centers in diamond indicates that diamond is gaining ground as a promising material for quantum computing and quantum simulation, and will become competitive with the other systems like ion traps.
(2) To investigate the functional role of non-trivial quantum effect in chemistry/biology, we have developed theories for the construction of a quantum sensor based on nitrogen-vacancy (NV) center in diamond, which offers the possibility to identify and investigate the role of coherence in e.g. spin chemistry and light harvesting complex.
Quantum metrology offers super-resolution and highly sensitive measurements of physical parameters on the strength of quantum coherence-enhanced precision. Color centers in diamond have been established as a highly sensitive room-temperature quantum sensor for minute physical quantities, such as magnetic/electric field and temperature, with nanometer spatial resolution thanks to its superior spin coherence properties and quantum control techniques. Usually, the precision of a quantum sensor requires the protection of quantum coherence from environment noise. We have particularly developed a robust continuous dynamical decoupling scheme that can be used (1) to image single electron/nuclear spins with a diamond quantum sensor under realistic environmental noise, (2) and to efficiently polarize nuclear spins, which can thereby significantly enhance the resolution of magnetic resonance imaging (MRI). A proof-of-principle experiment has also been demonstrated recently. These works would be useful towards the utilization of a nitrogen-vacancy center sensor to probing single electron/nucleus and thereby identifying quantum coherence in various biological processes, such as electron/energy transfer and radical pair based chemical magneto-reception. Our results were published in New J. Phys. 15, 013020 (2013), New J. Phys. 14, 113023 (2012), and Phys. Rev. Lett. 111, 067601 (2013).
(3) To investigate quantum effect in a representative example of quantum biology, namely radical pair mechanism for avian magneto-reception, we have used optimal control to exploit the principles for the optimal design of such a quantum magnetic compass. We have studied the role of coherence and decoherence in chemical magneto-reception. We showed that chemical magneto-reception is in essence similar to a quantum interferometer, and makes use of quantum coherence as a quantum device. This represents a crucial step to establish a direct connection between quantum coherence and biological process involved in avian magneto-reception. The results were published in Phys. Rev. A 85, 040304(Rapid Communication) (2012) and under review in Phys. Rev. Lett.