Quantum Properties Of Single-Photon Emitter Coupled To Surface Plasmon

An ideal single-photon source emits one and only one photon in a given time interval with a sub-Poissionian distribution. With the development of quantum information, we pursue more efficient single-photon source with long-term stability, high speed and narrow emission spectrum band. Single-photon source as an ideal information carrier can ensure the security of information communication in quantum cryptography. As an ideal computation qubit, it improves the possibility of creating powerful quantum computer. As an ideal anti-bunching source, it's always used to demonstrate the strangeness in quantum world. Up to now, we have observed the anti-bunching effect in many materials, such as single molecules, single quantum dots, single atoms and ions in a trap, and color centers in diamonds. However, all of them are difficult to apply in quantum information filed. So it's urgent to find an available and reliable single-photon source for the development of quantum information.The purpose of this thesis is to develop an ideal single-photon source which can be used in quantum cryptography. We proposed an experimental scheme of combining the surface plasmon technology in hot material field with the nitrogen vacancy color centers in diamond. The major work of this thesis is focused on studying the modification of quantum emission properties in single NV centers with coupling to gold nanoparticles and gold films. All of the work was undertaken by a homemade scanning confocal microscopy system with HBT setup contained. In this paper, the discussion about the improved saturation behavior in single quantum systems, the shortened lifetime on excitation state, the enhanced yield efficiency of single-photon are most emphasized. The achievements in this research are as follows:1. The saturation count rate of a single NV center on a gold film was two-fold higher while the saturation excitation power was decreased by 70%. So the absorption efficiency of the NV center has been improved.2. The average lifetime of a single NV center was just 11.2 ns, only half of that without coupling. So higher emission rate has been realized.3. Photodynamic analysis results revealed that the collection efficiency of a single NV center coupled to gold nanoparticles increased nearly three times, from 3.6% to 10.1%.In summary, the enhanced quantum emission properties of single NV centers demonstrated that the scheme of combining the surface plasmon technology with single quantum system will be available to develop an ideal single-photon source.