An official website of the United States government
Here’s how you know
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.
Atomic scale spectroscopy provides an exceptional ability to define electronic, optical, thermal, mechanical, and chemical properties of materials at the nanoscale. At these scales, dimensional confinement can lead to new and unusual properties, where the
Yuri Ralchenko, Alexander Kramida, Vladimir Azarov
Recent advance in calculations of energy levels of the 1s2l2l0 core-excited states for ions along the Li isoelectronic sequence from carbon to uranium suggested that theoretical predictions for the 1s22l-1s2l2l0 transitions are significantly more precise
Saleh Allehabi, Samuel Brewer, Vladimir Dzuba, Victor Flambaum, Kyle Beloy
We identify laser-accessible transitions in group 16-like highly charged ions as candidates for high-accuracy optical clocks, including S-, Se-, and Te-like systems. For this class of ions, the ground 3PJ fi ne structure manifold exhibits irregular
Ian Spielman, Graham Reid, Alina Pineiro Escalera, Amilson R. Fritsch, Mingwu Lu
Nontrivial topology in lattices is characterized by invariants---such as the Zak phase for one-dimensional (1D) lattices---derived from wave functions covering the Brillouin zone. We realized the 1D bipartite Rice--Mele (RM) lattice using ultracold 87-Rb
Xiaogang Zhang, Kyle Beloy, Youssef Hassan, William McGrew, Chun-Chia Chen, Jacob Siegel, Tanner Grogan, Andrew Ludlow
Laser cooling is a key ingredient for quantum control of atomic systems in a variety of settings. In two-valence-electron atoms, two-stage Doppler cooling is typically used to bring atoms to the μK regime. Here, we implement a pulsed radial cooling scheme
Ian Bell, Robin Fingerhut, Jadran Vrabec, Lorenzo Costigliola
It is shown that the residual entropy (entropy minus that of the ideal gas at the same temperature and density) is mostly synonymous with the independent variable of density scaling, identifying a direct link between these two approaches. The residual
Dmitry Fursa, Mark Zammit, Igor Bray, Liam Scarlett, Daniel Boyle, Yuri Ralchenko
We present cross sections for vibrational excitation via electronic excitation followed by radiative decay (ERD), for electrons scattering on all bound vibrational levels of the ground electronic state (X 1Σ+ g ) of molecular hydrogen and its isotopologues
Ting-Wei Hsu, Wenqi Zhu, Tobias Thiele, Mark Brown, Scott Papp, Amit Agrawal, Cindy Regal
Single neutral atoms in optical tweezers have become an important platform for quantum simulation, computing, and metrology [1-3]. With ground-up control similar to trapped ions, individual atoms can be prepared and entangled [2, 4, 5], and the scalability
Anthony M. Polloreno, Ana Maria Rey, John J. Bollinger
Trapped ions boast long coherence times, and excellent gate fidelities, making them a useful platform for quantum information processing. Scaling to larger numbers of ion qubits, potentially solved by photonic interconnects between Paul traps, or by
Ian Spielman, Mingwu Lu, Amilson R. Fritsch, Graham Reid, Alina Pineiro Escalera
We experimentally realized a time-periodically modulated 1D lattice for ultracold atoms featuring a pair of linear bands, each associated with a Floquet winding number: a topological invariant. These bands are spin-momentum locked and almost perfectly
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
Kamal Choudhary, Taner N. Yildirim, Daniel Siderius, A. Gilad Kusne, Austin McDannald, Diana Ortiz-Montalvo
The increasing CO$_2$ level is a critical concern and suitable materials are needed to directly capture such gases from the environment. While experimental and conventional computational methods are useful in finding such materials, they are usually slow
Michael Caouette-Mansour, Adrian Solyom, Brandon Ruffolo, Robert D. McMichael, Jack Childress (Sankey), Lilian Childress
Spin relaxometry with nitrogen-vacancy (NV) centers in diamond offers a spectrally selective, atomically localized, and calibrated measurement of microwave-frequency magnetic noise, presenting a versatile probe for condensed matter and biological systems
Nonlinearity is a powerful determinant of physical systems. Controlling nonlinearity leads to interesting states of matter and new applications. In optics, diverse families of continuous and discrete states arise from balance of nonlinearity and group
Shangjie Guo, Sophia Koh, Amilson R. Fritsch, Ian Spielman, Justyna Zwolak
In ultracold-atom experiments, data often comes in the form of images which suffer information loss inherent in the techniques used to prepare and measure the system. This is particularly problematic when the processes of interest are complicated, such as