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Entanglement of Four Particles



C A. Sackett, D Kielpinski, B E. King, Christopher Langer, V Meyer, C J. Myatt, M A. Rowe, Q A. Turchette, Wayne M. Itano, David J. Wineland, C Monroe


Quantum mechanics allows for many-particle wavefunctions that cannot be factorized into a product of single-particle wavefunctions, even when the constituent particles are entirely distinct. Such ‘entangled’ states explicitly demonstrate the non-local character of quantum theory, having potential applications in high-precision spectroscopy, quantum communication, cryptography and computation3. In general, the more particles that can be entangled, the more clearly nonclassical effects are exhibited—and the more useful the states are for quantum applications. Here we implement a recently proposed entanglement technique to generate entangled states of two and four trapped ions. Coupling between the ions is provided through their collective motional degrees of freedom, but actual motional excitation is minimized. Entanglement is achieved using a single laser pulse, and the method can in principle be applied to any number of ions.


Sackett, C. , Kielpinski, D. , King, B. , Langer, C. , Meyer, V. , Myatt, C. , Rowe, M. , Turchette, Q. , Itano, W. , Wineland, D. and Monroe, C. (2000), Entanglement of Four Particles, Nature, [online], (Accessed July 24, 2024)


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Created January 1, 2000, Updated February 17, 2017