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Quantum State Engineering of Light with Continuous-wave Optical Parametric Oscillators
Published on: May 30, 2014
Entanglement purification of gaussian continuous variable quantum states
1Institut fur Theoretische Physik, Universitat Innsbruck, A-6020 Innsbruck, Austria and Laboratory of Quantum Communication and Quantum Computation, University of Science and Technology of China, Hefei 230026, China.
Physical Review Letters
|October 6, 2000
Summary
This study introduces an efficient entanglement purification protocol using quantum nondemolition measurements. The method generates high-fidelity entangled states from less pure sources for quantum information applications.
Area of Science:
- Quantum Information Science
- Quantum Optics
- Entanglement Theory
Background:
- Entangled states are crucial for quantum information processing.
- Generating and maintaining high-fidelity entanglement is a significant challenge.
- Existing methods often suffer from low efficiency or require complex setups.
Purpose of the Study:
- To develop an efficient entanglement purification protocol.
- To generate maximally entangled states from less pure Gaussian continuous variable entangled states.
- To propose a practical optical implementation for the protocol.
Main Methods:
- Utilizing a local quantum nondemolition (QND) measurement.
- Measuring the total excitation number of several continuous variable entangled pairs.
- Employing cavity-enhanced cross-Kerr interactions for the QND measurement.
Main Results:
- High efficiencies in generating maximally entangled states.
- Applicability to both two-mode squeezed states and mixed Gaussian continuous entangled states.
- Demonstration of a feasible optical scheme for the proposed measurement.
Conclusions:
- The proposed protocol offers a viable route to high-fidelity entanglement purification.
- The optical scheme provides a practical pathway for experimental realization.
- This work advances the capabilities for creating robust entangled states for quantum technologies.
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