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: Varun Verma (Fed)

Search Title, Abstract, Conference, Citation, Keyword or Author
Displaying 26 - 50 of 147

State Readout of a Trapped Ion Qubit Using a Trap-integrated Superconducting Photon Detector

January 6, 2021
Author(s)
Susanna L. Todaro, Varun Verma, Katherine C. McCormick, David T. Allcock, Richard Mirin, David J. Wineland, Sae Woo Nam, Andrew C. Wilson, Dietrich Leibfried, Daniel Slichter
We detect fluorescence photons emitted by a single $^9$Be$^+$ ion confined in a surface- electrode rf ion trap, using a superconducting nanowire single photon detector integrated directly into the trap. We achieve a qubit readout fidelity of 99.91(1) %

Superconducting microwire detectors with single-photon sensitivity in the near-infrared

June 16, 2020
Author(s)
Jeffrey T. Chiles, Sonia M. Buckley, Adriana E. Lita, Varun B. Verma, Jeffrey M. Shainline, Richard P. Mirin, Sae Woo Nam, Jason Allmaras, Boris Korzh, Emma Wollman, Matthew Shaw
We report on the fabrication and characterization of single-photon-sensitive WSi superconducting detectors with wire widths from 1 υm to 3 υm. The devices achieve saturated internal detection efficiency at 1.55 υm wavelength and exhibit maximum count rates

Observation of an isomerizing double-well quantum system in the condensed phase

January 10, 2020
Author(s)
Varun Verma, Jascha A. Lau, Arnab Choudhury, Li Chen, Dirk Schwarzer, Alec M. Wodtke
Molecules are quantum objects; therefore, isomerization fundamentally involves quantum states bound within a molecular potential energy function with multiple minima. For isolated gas-phase molecules, eigenstates well above the isomerization saddle points

Tunable quantum beat of single photons enabled by nonlinear nanophotonics

November 22, 2019
Author(s)
Qing Li, Anshuman Singh, Xiyuan Lu, John Lawall, Varun Verma, Richard Mirin, Sae Woo Nam, Kartik Srinivasan
Integrated photonics is a promising approach for scalable implementation of diverse quantum resources at the chip-scale. Here, we demonstrate the integration of two essential building blocks for quantum information science - quantum sources and frequency

A kilopixel array of superconducting nanowire single-photon detectors

November 18, 2019
Author(s)
Varun Verma, Adriana Lita, Sae Woo Nam, R P. Mirin, Emma Wollman, William Farr, Matthew Shaw
We present a 1024-element imaging array of superconducting nanowire single photon detectors (SNSPDs) using a 32x32 row-column multiplexing architecture. Large arrays are desirable for applications such as imaging, spectroscopy, or particle detection.

Detecting Sub-GeV Dark Matter with Superconducting Nanowires

October 10, 2019
Author(s)
Varun Verma, Sae Woo Nam, Ilya Charaev, Marco Colangelo, Karl Berggren, Yonit Hochberg
We propose the use of superconducting nanowires as both target and sensor for direct detection of light dark matter. With excellent sensitivity to low-energy deposits on electrons, and demonstrated low dark counts, such devices could be used to probe

Quantum Frequency Conversion of a Quantum Dot Single-Photon Source on a Nanophotonic Chip

May 20, 2019
Author(s)
Anshuman Singh, Qing Li, Shunfa Liu, Ying Yu, Xiyuan Lu, Christian Schneider, Sven Hofling, John Lawall, Varun Verma, Richard Mirin, Sae Woo Nam, Jin Liu, Kartik Srinivasan
Single self-assembled InAs/GaAs quantum dots are promising bright sources of indistinguishable photons for quantum information science. However, their distribution in emission wavelength, due to inhomogeneous broadening inherent to their growth, has

Towards a source of entangled photon pairs in gallium phosphide

May 9, 2019
Author(s)
Paulina S. Kuo, Peter G. Schunemann, Mackenzie Van Camp, Varun B. Verma, Thomas Gerrits, Sae Woo Nam, Richard P. Mirin
We investigate parametric down-conversion in orientation-patterned GaP. Pumped at 865 nm, the signal and idler are at 1350 nm and 2400 nm, respectively.

Generating polarization-entangled photon pairs in domain-engineered PPLN

May 7, 2019
Author(s)
Paulina S. Kuo, Varun B. Verma, Thomas Gerrits, Sae Woo Nam, Richard P. Mirin
Using a periodically poled LiNbO3 crystal that is domain-engineered for two simultaneous type-II down-conversion processes, we demonstrated polarization-entangled photon-pair generation.