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Search Publications by: Stephen Eckel (Fed)

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Displaying 1 - 25 of 55

Efficient production of sodium Bose-Einstein condensates in a hybrid trap

September 10, 2025
Author(s)
Ian Spielman, Stephen Eckel, Gretchen Campbell, Yanda Geng, Shouvikl Mukherjee, Swarnav Banik, Monica Gutierrez~Galan, Hector Sosa-Martinez, Madison Anderson
We describe an apparatus that efficiently produces $^23}$Na Bose-Einstein condensates (BECs) in a hybrid trap that combines a quadrupole magnetic field with a far-detuned optical dipole trap. Using a Bayesian optimization framework, we systematically

Rayleigh-Taylor instability in a binary quantum fluid

August 27, 2025
Author(s)
Ian Spielman, Gretchen Campbell, Stephen Eckel, Yanda Geng, Junheng Tao, Mingshu Zhao, Shouvik Mukherjee
We experimentally investigated the Rayleigh-Taylor instability in an immiscible homogeneous Bose-Einstein condensate (BEC) in different spin states. A magnetic field gradient force pushes two BECs together and induces instability of the interface, leading

Compact Blackbody Radiation Atomic Sensor: Measuring Temperature using Optically Excited Atoms in Vapor Cells

April 17, 2025
Author(s)
David La Mantia, Mingxin Lei, Nikunjkumar Prajapati, Noah Schlossberger, Matthew Simons, Christopher Holloway, Julia Scherschligt, Stephen Eckel, Eric Norrgard
We demonstrate a blackbody radiation thermometer based on optically excited rubidium atoms in a vapor cell. Operating as a calibrated contact thermometer from 308K to 343 K, we realize temperature uncertainty as low as 0.04 %, and statistical temperature

Revisiting collisional broadening of $^85}$Rb Rydberg levels: conclusions for vapor cell manufacture

March 13, 2025
Author(s)
Mingxin Lei, Stephen Eckel, Eric Norrgard, Nikunjkumar Prajapati, Alexandra Artusio-Glimpse, Matthew Simons, Christopher Holloway
Electrometry based on electromagnetically induced transparency (EIT) in alkali Rydberg vapor cells may suffer reduced sensitivity due to spurious line broadening effects, caused by surface charges, contaminant gases, or other manufacturing defects. In

Effect of ''glancing'' collisions in the cold atom vacuum standard

February 12, 2025
Author(s)
Stephen Eckel, Daniel Barker, James A. Fedchak, Jacek Klos, Julia Scherschligt, Eite Tiesinga
We theoretically investigate the effect of "glancing" collisions on the ultra-high-vacuum pressure readings of the cold-atom vacuum standard (CAVS), based on either ultracold $^7$Li or $^87}$Rb atoms. Here, glancing collisions are those collisions between

Primary quantum thermometry of mm-wave blackbody radiation via induced state transfer in Rydberg states of cold atoms

January 23, 2025
Author(s)
Noah Schlossberger, Andrew Rotunno, Stephen Eckel, Eric Norrgard, Dixith Manchaiah, Nikunjkumar Prajapati, Alexandra Artusio-Glimpse, Samuel Berweger, Matthew Simons, Dangka Shylla, William Watterson, Charles Patrick, Adil Meraki, Rajavardhan Talashila, Amanda Younes, David La Mantia, Christopher Holloway
Rydberg states of alkali-metal atoms are highly sensitive to electromagnetic radiation in the GHz-to-THz regime because their transitions have large electric dipole moments. Consequently, environmental blackbody radiation (BBR) can couple Rydberg states to

Rydberg states of alkali atoms in atomic vapor as SI-traceable field probes and communications receivers

September 16, 2024
Author(s)
Noah Schlossberger, Samuel Berweger, Nikunjkumar Prajapati, Andrew Rotunno, Alexandra Artusio-Glimpse, Matthew Simons, Abrar Sheikh, Eric Norrgard, Stephen Eckel, Christopher Holloway
Rydberg states of alkali atoms are highly sensitive to electric fields because their electron wavefunction has a large spatial extent, leading to large polarizabilities for static fields and large transition dipole moments for time-varying fields. Over the

Spectroscopy of laser cooling transitions in MgF

August 23, 2024
Author(s)
Nickolas Pilgram, Benjamin Baldwin, David La Mantia, Stephen Eckel, Eric Norrgard
We measure the complete set of transition frequencies necessary to laser cool and trap MgF molecules. Specifically, we report the frequency of multiple low $J$ transitions of the $X^2\Sigma^+(v^\prime\prime}=0,1) \rightarrow A^2\Pi_1⁄2(v^\prime=0)$, $X^2

Rydberg states of alkali atoms in atomic vapor as SI-traceable field probes and communications receivers

May 8, 2024
Author(s)
Noah Schlossberger, Nik Prajapati, Samuel Berweger, Andrew Rotunno, Aly Artusio-Glimpse, Abrar Sheikh, Eric Norrgard, Christopher L. Holloway, Stephen Eckel
Rydberg states of alkali atoms are highly sensitive to electric fields because their electron wavefunction has a large spatial extent, leading to large polarizabilities for static fields and large transition dipole moments for time-varying fields

Rydberg states of alkali atoms in atomic vapor as SI-traceable field probes and communications receivers

May 8, 2024
Author(s)
Noah Schlossberger, Nik Prajapati, Samuel Berweger, Aly Artusio-Glimpse, Matt Simons, Abrar Sheikh, Andrew Rotunno, Eric Norrgard, Stephen Eckel, Christopher L. Holloway
Rydberg states of alkali atoms are highly sensitive to electric fields because their electron wavefunction has a large spatial extent, leading to large polarizabilities for static fields and large transition dipole moments for time-varying fields

Grating magneto-optical traps with complicated level structures

October 25, 2023
Author(s)
Daniel Barker, Peter Elgee, Ananya Sitaram, Eric Norrgard, Nikolai Klimov, Gretchen K. Campbell, Stephen Eckel
We study the forces and optical pumping within grating magneto-optical traps (MOTs) operating on transitions with non-trivial level structure. In contrast to the standard six-beam MOT configuration, rate equation modelling predicts that the asymmetric

Radiative Decay Rate and Branching Fractions of MgF

September 8, 2023
Author(s)
Eric Norrgard, Catherine Cooksey, Stephen Eckel, Nickolas Pilgram, Kayla Rodriguez, Howard W. Yoon, Yuly Andrea Chamorro Mena, Lukas Pasteka, Anastasia Borschevsky
Here we report measured and calculated values of radiative decay rates and vibrational branching fractions for the A$^2\Pi$ state of MgF. The decay rate measurements use time-correlated single photon counting with roughly 1\,\% total uncertainty. Branching

Simulations of a frequency-chirped magneto-optical trap of MgF

September 8, 2023
Author(s)
Kayla Rodriguez, Nickolas Pilgram, Daniel Barker, Stephen Eckel, Eric Norrgard
We simulate the capture process of MgF molecules into a frequency-chirped molecular MOT. Our calculations show that by chirping the frequency, the MOT capture velocity is increased by about of factor of 4 to 80m/s, allowing for direct loading from a two

Accurate measurement of the loss rate of cold atoms due to background gas collisions for the quantum-based cold atom vacuum standard

August 1, 2023
Author(s)
Daniel Barker, James A. Fedchak, Jacek Klos, Julia Scherschligt, Abrar Sheikh, Eite Tiesinga, Stephen Eckel
We present measurements of thermalized collisional rate coefficients for ultra-cold $^7$Li and $^87}$Rb colliding with room-temperature He, Ne, N$_2$, Ar, Kr, and Xe. In our experiments, a combined flowmeter and dynamic expansion system, a vacuum metrology

Precise Quantum Measurement of Vacuum with Cold Atoms

December 20, 2022
Author(s)
Daniel Barker, Bishnu Acharya, James A. Fedchak, Nikolai Klimov, Eric Norrgard, Julia Scherschligt, Eite Tiesinga, Stephen Eckel
We describe the cold-atom vacuum standards (CAVS) under development at the National Institute of Standards and Technology. The CAVS measures pressure in the ultra-high and extreme-high vacuum regimes by measuring the loss rate of sub-millikelvin sensor

A constant pressure flowmeter for the extremely high vacuum

August 9, 2022
Author(s)
Stephen Eckel, Daniel Barker, James A. Fedchak, Emmanuel Newsome, Julia Scherschligt, Robert E. Vest
We demonstrate operation of a constant-pressure flowmeter capable of generating and accurately measuring flows as low as $1\times10^-13}$mol/s. Generation of such small flows is accomplished by using a small conductance element with $C\approx 25$nL/s

Comparison of two multiplexed portable cold atom vacuum standards

July 15, 2022
Author(s)
Lucas Ehinger, Bishnu Acharya, Daniel Barker, James A. Fedchak, Julia Scherschligt, Eite Tiesinga, Stephen Eckel
We compare the vacuum measured by two portable cold atom vacuum standards (pCAVS) based on ultracold $^7$Li atoms. Our pCAVS devices share the same laser system and measure the vacuum concurrently. The two pCAVS together detected a leak with a rate on the

Laser Spectroscopy of the y7PJo states of Cr I

March 16, 2022
Author(s)
Eric Norrgard, Daniel Barker, Stephen Eckel, Sergey Porsev, Charles Cheung, Mikhail Kozlov, Ilya Tupitsyn, Marianna Safronova
Here we report measured and calculated values of decay rates of the 3d$^4$($^5$D)4s4p($^3$P$^\rmo}}$)\ y$^7$P$^\rmo}}_2,3,4}$ states of Cr I. The decay rates are measured using time-correlated single photon counting with roughly 1\,\% total uncertainty. In

Lambda-enhanced gray molasses in a tetrahedral laser beam geometry

March 14, 2022
Author(s)
Daniel Barker, Eric Norrgard, Nikolai Klimov, James A. Fedchak, Julia Scherschligt, Stephen Eckel
We report observation of sub-Doppler cooling of lithium using an irregular-tetrahedral laser beam arrangement, which is produced by a nanofabricated diffraction grating. We are able to capture 11(2) % of the lithium atoms from a grating magneto-optical

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
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