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Full-Text Articles in Optics

Optically Simulating A Quantum Associative Memory, John C. Howell, John A. Yeazell, Dan Ventura Sep 2000

Optically Simulating A Quantum Associative Memory, John C. Howell, John A. Yeazell, Dan Ventura

Mathematics, Physics, and Computer Science Faculty Articles and Research

This paper discusses the realization of a quantum associative memory using linear integrated optics. An associative memory produces a full pattern of bits when presented with only a partial pattern. Quantum computers have the potential to store large numbers of patterns and hence have the ability to far surpass any classical neural-network realization of an associative memory. In this work two three-qubit associative memories will be discussed using linear integrated optics. In addition, corrupted, invented and degenerate memories are discussed.


Two-Level Atom In An Optical Parametric Oscillator: Spectra Of Transmitted And Fluorescent Fields In The Weak Driving Field Limit, James P. Clemens, Perry R. Rice, Pranaw Kumar Rungta, Robert J. Brecha Aug 2000

Two-Level Atom In An Optical Parametric Oscillator: Spectra Of Transmitted And Fluorescent Fields In The Weak Driving Field Limit, James P. Clemens, Perry R. Rice, Pranaw Kumar Rungta, Robert J. Brecha

Physics Faculty Publications

We consider the interaction of a two-level atom inside an optical parametric oscillator. In the weak-driving-field limit, we essentially have an atom-cavity system driven by the occasional pair of correlated photons, or weakly squeezed light. We find that we may have holes, or dips, in the spectrum of the fluorescent and transmitted light. This occurs even in the strong-coupling limit when we find holes in the vacuum-Rabi doublet. Also, spectra with a subnatural linewidth may occur. These effects disappear for larger driving fields, unlike the spectral narrowing obtained in resonance fluorescence in a squeezed vacuum; here it is important that …


Quantum Computation Through Entangling Single Photons In Multipath Interferometers, John C. Howell, John A. Yeazell Jul 2000

Quantum Computation Through Entangling Single Photons In Multipath Interferometers, John C. Howell, John A. Yeazell

Mathematics, Physics, and Computer Science Faculty Articles and Research

Single-photon interferometry has been used to simulate quantum computations. Its use has been limited to studying few-bit applications due to rapid growth in physical size with numbers of bits. We propose a hybrid approach that employs n photons, each having L degrees of freedom yielding Ln basis states. The photons are entangled via a quantum nondemolition measurement. This approach introduces the essential element of quantum computing, that is, entanglement into the interferometry. Using these techniques, we demonstrate a controlled-NOT gate and a Grover's search circuit. These ideas are also applicable to the study of nonlocal correlations in many dimensions.


Entangling Macroscopic Quantum States, John C. Howell, John A. Yeazell Jun 2000

Entangling Macroscopic Quantum States, John C. Howell, John A. Yeazell

Mathematics, Physics, and Computer Science Faculty Articles and Research

Spatial entanglements of macroscopic quantum systems are proposed. The which-path uncertainty of a single photon passing through a beam splitter is transformed into the which-path uncertainty of two macroscopic fields via two quantum nondemolition measurements. The macroscopic fields are nonlocally correlated.


Reducing The Complexity Of Linear Optics Quantum Circuits, John C. Howell, John A. Yeazell Apr 2000

Reducing The Complexity Of Linear Optics Quantum Circuits, John C. Howell, John A. Yeazell

Mathematics, Physics, and Computer Science Faculty Articles and Research

Integrated optical elements can simplify the linear optics used to simulate quantum circuits. These linear optical simulations of quantum circuits have been developed primarily in terms of the free space optics associated with single-photon interferometry. For an L-bit simulation the number of required free-space optical elements is ∝2L if 50/50 beam splitters are used. The implementation (construction and alignment) of these circuits with these free-space elements is nontrivial. On the other hand, for the cases presented in this paper in which linear integrated optics (e.g., 2L×2L fiber couplers) are used, the number of optical devices does …