Dr. Matteo Nespol  (Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences)

Integrated Optics and Multiports: Manipulating Photonic Quantum States

Abstract:
Photons are appealing candidates for quantum computation, quantum key distribution and fundamental tests of the fundamental aspects of physics. Photonic quantum states lend themselves to different qubits encoding and many basic theorems and algorithms can be proven using entangled states with only a few photons. However, for truly being able to break the limits of current experimental techniques, we need a tool for producing the desired states, performing unitary transformations on them and measure them in appropriate basis. Such a device can be built with a suitable interferometric architecture that we shall call a multiport. As it can be demonstrated, any unitary operation on a N-dimensional Hilbert space can be performed on a photonic state by tuning a multiport internal parameters, opening virtually infinite possibilities for experimenting with high-dimensional multi-qubits states. Waveguides monolithically implemented on a crystal substrate are the platform of choice for implementing such a complex interferometer. Using lithium niobate, proton exchange guiding structures, we can build a scalable and stable universal state photonic quantum state manipulator, a powerful quantum-enabling technology.

2008 年 12 月 26 日
14:30~15:30

RM 111, New Physics Building