U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Search Publications by: Scott Glancy (Fed)

Search Title, Abstract, Conference, Citation, Keyword or Author
Displaying 1 - 25 of 40

Multi-mode Gaussian State Analysis with Total Photon Counting

July 11, 2023
Author(s)
Arik Avagyan, Scott Glancy, Emanuel Knill
The continuing improvement in the qualities of photon-number-resolving (PNR) detectors opens new possibilities for measuring quantum states of light. In this work we consider the question of what properties of an arbitrary multi-mode Gaussian state are

Constraints on Gaussian Error Channels and Measurements for Quantum Communication

April 10, 2023
Author(s)
Alexander T. Kwiatkowski, Ezad Shojaee, Sristy Agrawal, Akira Kyle, Curtis Rau, Scott Glancy, Emanuel Knill
Joint Gaussian measurements of two quantum systems are important for quantum communication between remote parties and are often used in continuous-variable teleportation or entanglement-swapping protocols. Many of the errors in real-world implementations

Quadrature Squeezing And Temperature Estimation From The Fock Distribution

November 3, 2022
Author(s)
Italo Pereira Bezerra, Hilma Vasconcelos, Scott Glancy
We present a method to estimate the amount of squeezing and temperature of a single-mode Gaussian harmonic oscillator state based on the weighted least squares estimator applied to measured Fock state populations. Squeezing and temperature, or equivalently

Improving quantum state detection with adaptive sequential observations

May 13, 2022
Author(s)
Emanuel Knill, Scott Glancy, Daniel Cole, Shawn Geller
For many quantum systems intended for information processing, one detects the logical state of a qubit by integrating a continuously observed quantity over time. For example, ion and atom qubits are typically measured by driving a cycling transition and

High-fidelity indirect readout of trapped-ion hyperfine qubits

April 21, 2022
Author(s)
Stephen Erickson, Jenny Wu, Panyu Hou, Daniel Cole, Shawn Geller, Alexander Kwiatkowski, Scott Glancy, Emanuel Knill, Daniel Slichter, Andrew C. Wilson, Dietrich Leibfried
We propose and demonstrate a protocol for high-fidelity indirect readout of trapped ion hyperfine qubits, where the state of a 9Be+ qubit ion is mapped to a 25Mg+ readout ion using laser-driven Raman transitions. By partitioning the 9Be+ ground-state

Multiphoton quantum metrology with neither pre- nor post-selected measurements

October 21, 2021
Author(s)
Chenglong You, Mingyuan Hong, Peter Bierhorst, Adriana Lita, Scott Glancy, Steven Kolthammer, Emanuel Knill, Sae Woo Nam, Richard Mirin, Omar Magana-Loaiza, Thomas Gerrits
The quantum statistical fluctuations of the electromagnetic field establish fundamental limits on the sensitivity of optical measurements. This fundamental limit, known as the shot-noise limit, imposes constraints on classical technologies, which can be

High-fidelity laser-free universal control of trapped ion qubits

September 8, 2021
Author(s)
Raghavendra Srinivas, Emanuel Knill, Robert Sutherland, Alexander T. Kwiatkowski, Hannah M. Knaack, Scott Glancy, David J. Wineland, Shaun C. Burd, Dietrich Leibfried, Andrew C. Wilson, David T. Allcock, Daniel Slichter
Universal control of multiple qubits—the ability to entangle qubits and to perform arbitrary individual qubit operations—is a fundamental resource for quantum computing, simulation and networking. Qubits realized in trapped atomic ions have shown the

Quantum gate teleportation between separated zones of a trapped-ion processor

May 31, 2019
Author(s)
Yong Wan, Daniel Kienzler, Stephen D. Erickson, Karl H. Mayer, Ting R. Tan, Jenny J. Wu, Hilma H. Macedo De Vasconcelos, Scott C. Glancy, Emanuel H. Knill, David J. Wineland, Andrew C. Wilson, Dietrich G. Leibfried
Large-scale quantum computers will inevitably require quantum gate operations between widely separated qubits, even within a single quantum information processing device. Nearly two decades ago, Gottesman and Chuang proposed a method for implementing such

Joint Quantum State and Measurement Tomography with Incomplete Measurements

October 12, 2018
Author(s)
Adam C. Keith, Charles H. Baldwin, Scott C. Glancy, Emanuel H. Knill
Estimation of quantum states and measurements is crucial for the implementation of quantum information protocols. The standard method for each is quantum tomography (QT). However, QT suffers from systematic errors caused by imperfect knowledge of the

Quadrature Histograms in Maximum Likelihood Quantum State Tomography

August 22, 2018
Author(s)
Leonardo E. Silva, Scott Glancy, Hilma H. Macedo De Vasconcelos
Quantum state tomography aims to determine the quantum state of a system from measured data and is an essential tool for quantum information science. When dealing with continuous variable quantum states of light, tomography is often done by measuring the

Experimentally Generated Random Numbers Certified by the Impossibility of Superluminal Signaling

April 11, 2018
Author(s)
Peter L. Bierhorst, Emanuel H. Knill, Scott C. Glancy, Yanbao Zhang, Alan Mink, Stephen P. Jordan, Andrea Rommal, Yi-Kai Liu, Bradley Christensen, Sae Woo Nam, Martin J. Stevens, Lynden K. Shalm
From dice to modern complex circuits, there have been many attempts to build increasingly better devices to generate random numbers. Today, randomness is fundamental to security and cryptographic systems, as well as safeguarding privacy. A key challenge

Chained Bell inequality experiment with high-efficiency measurements

March 28, 2017
Author(s)
Ting Rei Tan, Stephen D. Erickson, Peter L. Bierhorst, Daniel Kienzler, Scott C. Glancy, Emanuel H. Knill, Dietrich G. Leibfried, David J. Wineland, Yong Wan
We report correlation measurements on two 9Be+ ions that violate a chained Bell inequality obeyed by any local-realistic theory. The correlations can be modeled as derived from a mixture of a local-realistic probabilistic distribution and a distribution

Investigating Bias in Maximum Likelihood Quantum State Tomography

February 8, 2017
Author(s)
Scott C. Glancy, Hilma M. Vasconcelos, George B. Silva
Maximum likelihood quantum state tomography yields estimators that, in spite of the fact that they are consistent, may have bias. The bias of an estimator is the difference between the expected value of the estimate and the true value of the parameter

Preparation of entangled states through Hilbert space engineering

September 28, 2016
Author(s)
Yiheng Lin, John P. Gaebler, Florentin Reiter, Ting R. Tan, Ryan S. Bowler, Yong Wan, Adam C. Keith, Emanuel Knill, Kevin Coakley, Dietrich Leibfried, David J. Wineland, Scott Glancy
Entangled states are a crucial resource for quantum-based technologies such as quantum computers and quantum communication systems. Exploring new methods for entanglement generation is important for diversifying and eventually improving current approaches

High Fidelity Universal Gate Set for 9Be+ Ion Qubits

August 4, 2016
Author(s)
John P. Gaebler, Ting R. Tan, Yong Wan, Yiheng Lin, Ryan S. Bowler, Adam C. Keith, Scott Glancy, Kevin Coakley, Emanuel Knill, Dietrich Leibfried, David J. Wineland
We report high-fidelity laser-beam-induced quantum logic gates on qubits comprised of hyperfine states in 9Be+ ions, achieved in part through a combination of improved laser beam quality and control and improved state preparation. We demonstrate single

A strong loophole-free test of local realism

December 16, 2015
Author(s)
Lynden K. Shalm, Evan Meyer-Scott, B. G. Christensen, Peter L. Bierhorst, Michael A. Wayne, Deny Hamel, Martin J. Stevens, Thomas Gerrits, Scott C. Glancy, Michael S. Allman, Kevin J. Coakley, Shellee D. Dyer, Adriana E. Lita, Varun B. Verma, Joshua C. Bienfang, Alan L. Migdall, Yanbao Zhang, William Farr, Francesco Marsili, Matthew D. Shaw, Jeffrey Stern, Carlos Abellan, Waldimar Amaya, Valerio Pruneri, Thomas Jennewein, Morgan Mitchell, P. G. Kwiat, Richard P. Mirin, Emanuel H. Knill, Sae Woo Nam
We present a loophole-free violation of local realism using entangled photon pairs. We ensure that all relevant events in our Bell test are spacelike separated by placing the parties far enough apart and by using fast random number generators and high

Analysis of coincidence-time loopholes in experimental Bell tests

March 4, 2015
Author(s)
B. G. Christensen, A. Hill, P. G. Kwiat, Emanuel Knill, Sae Woo Nam, Kevin Coakley, Scott Glancy, Krister Shalm, Y. Zhang
We apply a distance-based Bell-test analysis method ["Bell inequalities for continuously emitting sources" E. Knill et al. arXiv:14097732 (2014)] to three experimental data sets where conventional analyses failed or required additional assumptions. The

Bell Inequalities for Continuously Emitting Sources

March 4, 2015
Author(s)
Emanuel H. Knill, Scott C. Glancy, Sae Woo Nam, Kevin J. Coakley, Yanbao Zhang
A common experimental strategy for demonstrating non-classical correlations is to show violation of a Bell inequality by measuring a continuously emitted stream of entangled photon pairs. The measurements involve the detection of photons by two spatially

Third-order antibunching from an imperfect single-photon source

February 4, 2014
Author(s)
Martin J. Stevens, Scott C. Glancy, Sae Woo Nam, Richard P. Mirin
We measure second- and third-order temporal coherences, g(2)(τ) and g(3)(τ1,τ2), of an optically excited single-photon source: an InGaAs quantum dot in a microcavity pedestal. Increasing the optical excitation power leads to an increase in the measured

Third-order antibunching from an imperfect single-photon source

February 4, 2014
Author(s)
Martin J. Stevens, Scott C. Glancy, Sae Woo Nam, Richard P. Mirin
We measure second- and third-order temporal coherences, g (2)(τ) and g (3)(τ1, τ2), of an optically excited single-photon source: an InGaAs quantum dot in a microcavity pedestal. Increasing the optical excitation power leads to an increase in the measured

Efficient quantification of experimental evidence against local realism

November 18, 2013
Author(s)
Yanbao Zhang, Scott C. Glancy, Emanuel H. Knill
To statistically quantify the evidence against local realism in an experiment, it is desirable to bound the probability according to local realism of a violation at least as high as that observed. We describe an efficient protocol for computing such a

Gradient-based stopping rules for maximum-likelihood quantum-state tomography

September 18, 2012
Author(s)
Scott C. Glancy, Emanuel H. Knill, Mark Girard
When performing maximum likelihood quantum state tomography, one must find the quantum state that maximizes the likelihood for observed measurements on identically prepared systems, all having that quantum state. This optimization is usually performed with

Asymptotically Optimal Confidences for Rejecting Local Realism

December 22, 2011
Author(s)
Yanbao Zhang, Scott Glancy, Emanuel Knill
Reliable experimental demonstrations of violations of local realism are highly desirable for fundamental tests of Quantum Mechanics. Such violations can be quantified in terms of a confidence for rejecting local realism. We propose a method for computing

Generation and characterization of high-purity, pulsed squeezed light at telecom wavelengths from pp-KTP

November 15, 2011
Author(s)
Thomas Gerrits, Martin J. Stevens, Burm Baek, Brice R. Calkins, Adriana E. Lita, Scott C. Glancy, Emanuel H. Knill, Sae Woo Nam, Richard P. Mirin, Robert Hadfield, Ryan Bennink, Warren Grice, Sander N. Dorenbos, Tony Zijlstra, Teun Klapwijk, Val Zwiller
We characterize a pp-KTP crystal designed to produce pure single mode squeezed vacuum at 1570 nm. Measurements show a raw (corrected) Hong-Ou-Mandel interference with 86 % (90 %) visibility and a circular joint spectral probability distribution with a