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Search Publications by: Stephen Eckel (Fed)

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Displaying 26 - 50 of 94

Accurate Determination of Hubble Attenuation and Amplification in Expanding and Contracting Cold-Atom Universes

February 28, 2022
Author(s)
Swarnav Banik, Monica Gutierrez Galan, Hector Sosa Martinez, 1, Madison Anderson, Stephen Eckel, Ian Spielman, Gretchen K. Campbell
In the expanding universe, relativistic scalar fields are thought to be attenuated by "Hubble friction," which results from the dilation of the underlying spacetime metric. By contrast, in a contracting universe this pseudofriction would lead to

Erratum: Collisions of room temperature helium with ultra-cold lithium and the van-der-Waals bound state of HeLi [Phys. Rev. A 101, 012702 (2020)]

February 28, 2022
Author(s)
Constantinos Makrides, Daniel Barker, James A. Fedchak, Julia Scherschligt, Stephen Eckel, Eite Tiesinga
We have found an error in the computation of the thermally-averaged total elastic rate coefficient for the collision of a room-temperature helium atom with an ultra-cold lithium atom presented. We omitted the factor $2/\sqrt\pi}$ in the normalization over

Progress towards comparison of quantum and classical vacuum standards

September 22, 2021
Author(s)
Daniel Barker, Nikolai Klimov, Eite Tiesinga, James A. Fedchak, Julia Scherschligt, Stephen Eckel
We present our progress towards a comparison of NIST's cold atom primary vacuum standard and a dynamic expansion vacuum standard. The cold atom vacuum standard (CAVS) converts the loss rate of atoms from a magnetic trap to a vacuum pressure using ab initio

Quantum-Based Photonic Sensors for Pressure, Vacuum, and Temperature Measurements: A Vison of the Future with NIST on a Chip

September 17, 2021
Author(s)
Jay H. Hendricks, Zeeshan Ahmed, Daniel Barker, Kevin O. Douglass, Stephen Eckel, James A. Fedchak, Nikolai Klimov, Jacob Edmond Ricker, Julia Scherschligt
The NIST on a Chip (NOAC) program's central idea is the idea that measurement technology can be developed to enable metrology to be performed "outside the National Metrology Institute" by the crea-tion of deployed and often miniaturized standards. These

PyLCP: A python package for computing laser cooling physics

September 9, 2021
Author(s)
Stephen Eckel, Daniel Barker, Eric Norrgard, Julia Scherschligt
We present a python object-oriented computer program for simulating various aspects of laser cooling physics. Our software is designed to be both easy to use and adaptable, allowing the user to specify the level structure, magnetic field profile, or the

NIST on a Chip: Photonic and Quantum-Based Sensors for Measurements of Pressure, Vacuum, Temperature and Beyond!

April 29, 2021
Author(s)
Jay H. Hendricks, Zeeshan Ahmed, Daniel Barker, Stephen Eckel, James A. Fedchak, Nikolai Klimov, Julia Scherschligt
At the core of the NIST on a Chip (NoAC) program is the idea that measurement technology can be developed to enable metrology to be done "outside the National Metrology Institute" by virtue of deployed and often miniaturized standards (that can also serve

Outgassing rate comparison of seven geometrically similar vacuum chambers of different materials and heat treatments

April 23, 2021
Author(s)
James A. Fedchak, Julia Scherschligt, Sefer Avdiaj, Daniel Barker, Stephen Eckel, Ben Bowers, Scott O'Connell, Perry Henderson
We have measured the water and hydrogen outgassing rates of seven vacuum chambers of identical geometry but constructed of different materials and heat treatments. Chambers of five different materials were tested: 304L, 316L, and 316LN stainless steels

Blackbody Radiation Noise Broadening of Quantum Systems

April 22, 2021
Author(s)
Eric B. Norrgard, Stephen Eckel, Christopher L. Holloway, Eric L. Shirley
Precision measurements of quantum systems often seek to probe or must account for the interaction with blackbody radiation. Over the past several decades, much attention has been given to AC Stark shifts and stimulated state transfer. For a blackbody in

Quantum Blackbody Thermometry

April 22, 2021
Author(s)
Eric B. Norrgard, Stephen Eckel, Christopher L. Holloway, Eric L. Shirley
Blackbody radiation (BBR) sources are calculable radiation sources that are frequently used in radiometry, temperature dissemination, and remote sensing. Despite their ubiquity, blackbody sources, have a plethora of systematics (e.g., emissivity

Phonon redshift and Hubble friction in an expanding BEC

March 11, 2021
Author(s)
Stephen Eckel, Ted Jacobson
We revisit the theoretical analysis of an expanding ring-shaped Bose-Einstein condensate. Starting from the action and integrating over dimensions orthogonal to the phonon's direction of travel, we derive an effective one-dimensional wave equation for

Note: A Bitter-type electromagnet for complex atomic trapping and manipulation

February 12, 2021
Author(s)
Jacob L. Siegel, Daniel Barker, James A. Fedchak, Julia Scherschligt, Stephen Eckel
We create a pair of symmetric Bitter-type electromagnet assemblies capable of producing multiple field configurations including uniform magnetic fields, spherical quadruple traps, or Ioffe-Pritchard magnetic bottles. Unlike other designs, our coil allows

Magneto-optical trapping using planar optics

January 29, 2021
Author(s)
William McGehee, Wenqi Zhu, Daniel Barker, Daron Westly, Alexander Yulaev, Nikolai Klimov, Amit Agrawal, Stephen Eckel, Vladimir Aksyuk, Jabez J. McClelland
Laser-cooled atoms are a key component of many calibration-free measurement platforms— including clocks, gyroscopes, and gravimeters—and are a promising technology for quantum networking and quantum computing. The optics and vacuum hardware required to

Note: A Radio Frequency Voltage-Controlled Current Source for Quantum Spin Manipulation

October 19, 2020
Author(s)
Daniel S. Barker, Alessandro Restelli, James A. Fedchak, Julia K. Scherschligt, Stephen P. Eckel
We present a design for a wide-bandwidth, voltage-controlled current source that is easily integrated with radiofrequency magnetic field coils. Our design uses current feedback to compensate for the frequency-dependent impedance of a radiofrequency antenna