1.8k citations · 16.3k across the 107 of their papers we have counts for
92 papers · 1 filter
Towards a resolution of the spin alignment problem
Mohammad A. Alhejji, Emanuel Knill
Consider minimizing the entropy of a mixture of states by choosing each state subject to constraints. If the spectrum of each state is fixed, we expect that in order to reduce the…
Multi-mode Gaussian State Analysis with Total Photon Counting
Arik Avagyan, Emanuel Knill, Scott Glancy
The continuing improvement in the qualities of photon-number-resolving detectors opens new possibilities for measuring quantum states of light. In this work we consider the questio…
Constraints on Gaussian Error Channels and Measurements for Quantum Communication
Alex Kwiatkowski, Ezad Shojaee, Sristy Agrawal +4
Joint Gaussian measurements of two quantum systems can be used for quantum communication between remote parties, as in teleportation or entanglement swapping protocols. Many types…
Improving quantum state detection with adaptive sequential observations
Shawn Geller, Daniel C. Cole, Scott Glancy +1
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 a…
High-fidelity indirect readout of trapped-ion hyperfine qubits
Stephen D. Erickson, Jenny J. Wu, Pan-Yu Hou +8
We propose and demonstrate a protocol for high-fidelity indirect readout of trapped ion hyperfine qubits, where the state of a qubit ion is mapped to a $^{25}\text{…
High-fidelity laser-free universal control of two trapped ion qubits
R. Srinivas, S. C. Burd, H. M. Knaack +9
Universal control of multiple qubits -- the ability to entangle qubits and to perform arbitrary individual qubit operations -- is a fundamental resource for quantum computation, si…
Scalable multiphoton quantum metrology with neither pre- nor post-selected measurements
Chenglong You, Mingyuan Hong, Peter Bierhorst +8
The quantum statistical fluctuations of the electromagnetic field establish a limit, known as the shot-noise limit, on the sensitivity of optical measurements performed with classi…
Direct observation of deterministic macroscopic entanglement
Shlomi Kotler, Gabriel A. Peterson, Ezad Shojaee +9
Quantum entanglement of mechanical systems emerges when distinct objects move with such a high degree of correlation that they can no longer be described separately. Although quant…
Device-independent Randomness Expansion with Entangled Photons
Lynden K. Shalm, Yanbao Zhang, Joshua C. Bienfang +12
With the growing availability of experimental loophole-free Bell tests, it has become possible to implement a new class of device-independent random number generators whose output…
Certified Quantum Measurement of Majorana Fermions
Abu Ashik Md. Irfan, Karl Mayer, Gerardo Ortiz +1
We present a quantum self-testing protocol to certify measurements of fermion parity involving Majorana fermion modes. We show that observing a set of ideal measurement statistics…
Quantum gate teleportation between separated qubits in a trapped-ion processor
Yong Wan, Daniel Kienzler, Stephen D. Erickson +9
Large-scale quantum computers will require quantum gate operations between widely separated qubits. A method for implementing such operations, known as quantum gate teleportation (…
Approximate exchange-only entangling gates for the three-spin- decoherence-free subsystem
James. R. van Meter, Emanuel Knill
The three-spin- decoherence-free subsystem defines a logical qubit protected from collective noise and supports exchange-only universal gates. Such logical qubits are well-sui…
Experimental Low-Latency Device-Independent Quantum Randomness
Yanbao Zhang, Lynden K. Shalm, Joshua C. Bienfang +10
Applications of randomness such as private key generation and public randomness beacons require small blocks of certified random bits on demand. Device-independent quantum random n…
Certifying Quantum Randomness by Probability Estimation
Yanbao Zhang, Emanuel Knill, Peter Bierhorst
We introduce probability estimation, a broadly applicable framework to certify randomness in a finite sequence of measurement results without assuming that these results are indepe…
Quantum Probability Estimation for Randomness with Quantum Side Information
Emanuel Knill, Yanbao Zhang, Honghao Fu
We develop a quantum version of the probability estimation framework [arXiv:1709.06159] for randomness generation with quantum side information. We show that most of the properties…
Quantum Process Fidelity Bounds from Sets of Input States
Karl Mayer, Emanuel Knill
We investigate the problem of bounding the quantum process fidelity given bounds on the fidelities between target states and the action of a process on a set of pure input states.…
Challenging local realism with human choices
The BIG Bell Test Collaboration, C. Abellán, A. Acín +105
A Bell test is a randomized trial that compares experimental observations against the philosophical worldview of local realism. A Bell test requires spatially distributed entanglem…
Experimentally Generated Randomness Certified by the Impossibility of Superluminal Signals
Peter Bierhorst, Emanuel Knill, Scott Glancy +9
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 an…
Quantum Randomness Generation by Probability Estimation with Classical Side Information
Emanuel Knill, Yanbao Zhang, Peter Bierhorst
We develop a framework for certifying randomness from Bell-test trials based on directly estimating the probability of the measurement outcomes with adaptive test supermartingales.…
Experimentally Generated Random Numbers Certified by the Impossibility of Superluminal Signaling
Peter Bierhorst, Emanuel Knill, Scott Glancy +7
Random numbers are an important resource for applications such as numerical simulation and secure communication. However, it is difficult to certify whether a physical random numbe…
Chained Bell Inequality Experiment with High-Efficiency Measurements
T. R. Tan, Y. Wan, S. Erickson +6
We report correlation measurements on two Be ions that violate a chained Bell inequality obeyed by any local-realistic theory. The correlations can be modeled as derived fr…
High-Fidelity Universal Gate Set for Be Ion Qubits
J. P. Gaebler, T. R. Tan, Y. Lin +8
We report high-fidelity laser-beam-induced quantum logic gates on magnetic-field-insensitive qubits comprised of hyperfine states in Be ions with a memory coherence time…
A strong loophole-free test of local realism
Lynden K. Shalm, Evan Meyer-Scott, Bradley G. Christensen +31
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 parti…
Bell Inequalities for Continuously Emitting Sources
Emanuel Knill, Scott Glancy, Sae Woo Nam +2
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…