Gate fidelity fluctuations and quantum process invariants (2009)
Magesan, Easwar, Blume-Kohout, Robin, Emerson, Joseph
We characterize the quantum gate fidelity in a state-independent manner by giving explicit expressions for the variance and a method for calculating all moments of the gate fidelity. We discuss a...
Three Slit Experiments and the Structure of Quantum Theory (2009)
Ududec, Cozmin, Barnum, Howard, Emerson, Joseph
In spite of the interference manifested in the double-slit experiment, quantum theory predicts that a measure of interference defined by Sorkin and involving various outcome probabilities from an...
Based upon the a critical review of three purposefully selected studies the author opines that professors within educational leadership programs have an obligation to encourage future administrators...
Based upon the a critical review of three purposefully selected studies the author opines that professors within educational leadership programs have an obligation to encourage future administrators...
Framed Hilbert space: hanging the quasi-probability pictures of quantum theory (2009)
Ferrie, Christopher, Emerson, Joseph
Building on earlier work, we further develop a formalism based on the mathematical theory of frames that defines a set of possible phase-space or quasi-probability representations of...
Reformers or Roadblocks: Educational Interest Groups and State Policy Formation (2008)
Joseph Emerson, Linda Lemasters, Everett Howerton
Given the overt political nature of this topic, an additional theoretical postulate, the Triadic Theory of Power was also presented as another framework to conceptualize the external and internal...
Ferrie, Christopher, Emerson, Joseph
Several finite dimensional quasi-probability representations of quantum states have been proposed to study various problems in quantum information theory and quantum foundations. These...
Experimentally scalable protocol for identification of correctable codes (2007)
Silva, Marcus, Magesan, Easwar, Kribs, David W., Emerson, Joseph
The task of finding a correctable encoding that protects against some physical quantum process is in general hard. Two main obstacles are that an exponential number of experiments are needed to gain...
Symmetrised Characterisation of Noisy Quantum Processes (2007)
Emerson, Joseph, Silva, Marcus, Moussa, Osama, Ryan, Colm, Laforest, Martin, Baugh, Jonathan, ...
A major goal of developing high-precision control of many-body quantum systems is to realise their potential as quantum computers. Probably the most significant obstacle in this direction is the...
Signatures of incoherence in a quantum information processor (2007)
Henry, Michael K., Gorshkov, Alexey V., Weinstein, Yaakov S., Cappellaro, Paola, Emerson, Joseph, Boulant, Nicolas, ...
Incoherent noise is manifest in measurements of expectation values when the underlying ensemble evolves under a classical distribution of unitary processes. While many incoherent processes appear...
Quantum t-designs: t-wise independence in the quantum world (2007)
Ambainis, Andris, Emerson, Joseph
A t-design for quantum states is a finite set of quantum states with the property of simulating the Haar-measure on quantum states, w.r.t. any test that uses at most t copies of a state. We give...
Efficient error characterization in Quantum Information Processing (2006)
Lévi, Benjamin, López, Cecilia C., Emerson, Joseph, Cory, D. G.
We describe how to use the fidelity decay as a tool to characterize the errors affecting a quantum information processor through a noise generator $G_{\tau}$. For weak noise, the initial decay rate...
Exact and Approximate Unitary 2-Designs: Constructions and Applications (2006)
Dankert, Christoph, Cleve, Richard, Emerson, Joseph, Livine, Etera
We consider an extension of the concept of spherical t-designs to the unitary group in order to develop a unified framework for analyzing the resource requirements of randomized quantum algorithms....
Study of localization in the quantum sawtooth map emulated on a quantum information processor (2005)
Henry, Michael K., Emerson, Joseph, Martinez, Rudy, Cory, David G.
Quantum computers will be unique tools for understanding complex quantum systems. We report an experimental implementation of a sensitive, quantum coherence-dependent localization phenomenon on a...
Scalable Noise Estimation with Random Unitary Operators (2005)
Emerson, Joseph, Alicki, Robert, Zyczkowski, Karol
We describe a scalable stochastic method for the experimental measurement of generalized fidelities characterizing the accuracy of the implementation of a coherent quantum transformation. The method...
Convergence Conditions for Random Quantum Circuits (2005)
Emerson, Joseph, Livine, Etera, Lloyd, Seth
Efficient methods for generating pseudo-randomly distributed unitary operators are needed for the practical application of Haar distributed random operators in quantum communication and noise...
Entanglement Assisted Metrology (2004)
Cappellaro, Paola, Emerson, Joseph, Boulant, Nicolas, Ramanathan, Chandrasekhar, Lloyd, Seth, Cory, David G.
We propose a new approach to the measurement of a single spin state, based on nuclear magnetic resonance (NMR) techniques and inspired by the coherent control over many-body systems envisaged by...
Random Quantum Circuits and Pseudo-Random Operators: Theory and Applications (2004)
Pseudo-random operators consist of sets of operators that exhibit many of the important statistical features of uniformly distributed random operators. Such pseudo-random sets of operators are most...
Quantum Process Tomography of the Quantum Fourier Transform (2004)
Weinstein, Yaakov S., Havel, Timothy F., Emerson, Joseph, Boulant, Nicolas, Saraceno, Marcos, Lloyd, Seth, ...
The results of quantum process tomography on a three-qubit nuclear magnetic resonance quantum information processor are presented, and shown to be consistent with a detailed model of the...
Estimation of the Local Density of States on a Quantum Computer (2003)
Emerson, Joseph, Lloyd, Seth, Poulin, David, Cory, David
We report an efficient quantum algorithm for estimating the local density of states (LDOS) on a quantum computer. The LDOS describes the redistribution of energy levels of a quantum system under the...
Robust Control of Quantum Information (2003)
Pravia, Marco A., Boulant, Nicolas, Emerson, Joseph, Farid, Amro, Fortunato, Evan M., Havel, Timothy F., ...
Errors in the control of quantum systems may be classified as unitary, decoherent and incoherent. Unitary errors are systematic, and result in a density matrix that differs from the desired one by a...
Quantum Chaos and Quantum-Classical Correspondence (2002)
The quantum dynamics of a classically chaotic model are studied in the approach to the macroscopic limit. The quantum predictions are compared and contrasted with the classical predictions of both...
Fidelity Decay as an Efficient Indicator of Quantum Chaos (2002)
Emerson, Joseph, Weinstein, Yaakov S., Lloyd, Seth, Cory, D. G.
Recent work has connected the type of fidelity decay in perturbed quantum models to the presence of chaos in the associated classical models. We demonstrate that a system's rate of fidelity decay...
Rheumatic peritonitis /--Joseph Emerson. (1883)
Handwritten thesis submitted in partial fulfillment of the requirements of the degree of M.D.