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Physics

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Displaying 1 - 25 of 4522

Broadband Optoelectronic Mixer for Terahertz Frequency-Comb Measurements

May 5, 2025
Author(s)
Jizhao Zang, Jesse Morgan, Andreas Beling, Scott Papp
We demonstrate ultra-broadband optoelectronic mixing of frequency combs that provides phase-coherent detection of a repetition frequency up to 500 GHz, using a high-speed modified uni-traveling carrier (MUTC) photodiode. Nonlinear photo-electron effects in

CODATA Recommended Values of the Fundamental Physical Constants: 2022

April 30, 2025
Author(s)
Peter Mohr, David Newell, Barry N. Taylor, Eite Tiesinga
We report the 2022 self-consistent values of constants and conversion factors of physics and chemistry recommended by the Committee on Data of the International Science Council (CODATA). The recommended values can also be found at physics.nist.gov

Dynamically generated concatenated codes and their phase diagrams

April 24, 2025
Author(s)
Grace Sommers, David Huse, Michael Gullans
We formulate code concatenation as the action of a unitary quantum circuit on an expanding tree geometry and find that for certain classes of gates, applied identically at each node, a binary tree circuit encodes a single logical qubit with code distance

High-Stability Single-Ion Clock with 5.5 x 10^-19 Systematic Uncertainty

April 21, 2025
Author(s)
Mason Marshall, Daniel Rodriguez Castillo, Willa Dworschack, Alexander Aeppli, Kyungtae Kim, Dahyeon Lee, William Warfield, Nicholas Nardelli, Tara Fortier, Jun Ye, David Ray Leibrandt, David Hume
We report a single-ion optical atomic clock with fractional frequency uncertainty of 5.5 x 10^-19 and frequency stability of 3.5 x 10^-16/sqrttau/s}, based on quantum logic spectroscopy of a single 27Al+ ion. A co-trapped 25Mg+ ion provides sympathetic

NIST Time and Frequency Bulletin

April 7, 2025
Author(s)
Kelsey Rodriguez
The Time and Frequency Bulletin provides information on performance of time scales and a variety of broadcasts (and related information) to users of the NIST services.

METROLOGY FOR MRI: THE FIELD YOU'VE NEVER HEARD OF

March 19, 2025
Author(s)
Kathryn Keenan, Stephen Russek, Matt Hall
Quantitative MRI has been an active area of research for decades and has produced a huge range of approaches with enormous potential for patient benefit. In many cases, however, there are challenges with reproducibility which has hampered clinical

Detection of fractional quantum Hall states by entropy-sensitive measurements

March 17, 2025
Author(s)
Nishat Sultana, Robert Rienstra, K Watanabe, T Taniguchi, Joseph Stroscio, Nikolai Zhitenev, D Feldman, Fereshte Ghahari Kermani
Measurements of the thermopower of a clean two-dimensional electron system is directly proportional to the entropy per charge carrier1 which can probe strongly interacting quantum systems ranging from black holes2 to the fractional quantum Hall effect

Quantum Monte Carlo and density functional theory study of strain and magnetism in 2D 1T-VSe2 with charge density wave states

March 7, 2025
Author(s)
Daniel Wines, Akram Ibrahim, Nishwanth Gudibandla, Tehseen Adel, Frank Abel, Sharadh Jois, Kayahan Saritas, Jaron Krogel, Li Yin, Tom Berlijn, Aubrey Hanbicki, Gregory Stephen, Adam Friedman, Sergiy Krylyuk, Albert Davydov, Brian Donovan, Michelle Jamer, Angela Hight Walker, Kamal Choudhary, Francesca Tavazza, Can Ataca
Two-dimensional (2D) 1T-VSe2 has prompted significant interest due to the discrepancies regarding alleged ferromagnetism (FM) at room temperature, charge density wave (CDW) states and the interplay between the two. We employed a combined Diffusion Monte

Modulated Laser Thermal Interrogation (MLTI): A Novel In Situ Metal Powder Evaluation Technique for Laser Powder Bed Fusion

March 1, 2025
Author(s)
Sina Ghadi, Xiaobo Chen, Nicholas Tomasello, Nicholas Derimow, Srikanth Rangarajan, Guangwen Zhou, Scott Schiffres
Assessment of metal powders in powder bed additive manufacturing is crucial, as the quality of the powders significantly impacts the final printed parts. This study introduces a novel technique to characterize metal powders by analyzing changes in their

Kolmogorov turbulence in atomic Bose-Einstein condensates

February 25, 2025
Author(s)
Ian Spielman, Mingshu Zhao, Junheng Tao
We investigated turbulence in atomic Bose-Einstein condensates (BECs) using a minimally destructive, impurity injection technique analogous to particle image velocimetry in conventional fluids. Our approach transfers small regions of the BEC into a

Measurement resolution enhanced coherence for lattice fermions

February 25, 2025
Author(s)
Ian Spielman, Hilary Hurst, Yik Teoh
Weak measurement enables the extraction of targeted information from a quantum system while minimizing decoherence due to measurement backaction. However, in many-body quantum systems backaction can have unexpected effects on wavefunction collapse. We

System Vicarious Calibration for climate and global long-term operational ocean color applications

February 25, 2025
Author(s)
Giuseppe Zibordi, B. Carol Johnson, Ewa Kwiatkowska, Kenneth Voss, David Antoine, Sean William Bailey, Andrew Barnard, Brian Barnes, Agnieszka Bialek, Shuguo Chen, Susanne Craig, Constant Mazeran, FREDERIC MELIN, Jee-Eun Min, Hiroshi Murakami, Menghua Wang
System Vicarious Calibration (SVC) enhances the accuracy of satellite ocean color radiometric data products by removing the bias due to the intrinsic inaccuracies affecting both the responsivity of the space sensor and the correction for the atmospheric

Mechanical Sensors for Planck-scale Dark Matter Searches via Long-range Forces

February 14, 2025
Author(s)
Jacob Taylor, Juehang Qin, Dorian Amaral, sunil bhave, Erqian Cai, Daniel Carney, Raphael Lang, Shengchao Li, Claire Marvinney, Alberto Marino, Jared Newton, Christopher Tunnell
Dark matter candidates with masses around the Planck-scale are theoretically well-motivated and have been the subject of numerous studies; it has also been suggested that it might be possible to search for dark matter solely via gravitational interactions

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

Cryogenic photonic resonator with 10-17/s drift

February 11, 2025
Author(s)
Wei Zhang, William Milner, Jun Ye, Scott Papp
Thermal noise is the predominant instability in the provision of ultrastable laser frequency by reference to a cavity. Reducing the thermal-noise limit of a cavity means either making it larger to spread thermal fluctuations, reducing the sensitivity of

Nanophotonic oscillators for laser conversion beyond an octave

February 11, 2025
Author(s)
Grant Brodnik, Haixin Liu, David Carlson, Jennifer Black, Scott Papp
Many uses of lasers place the highest importance on access to specific wavelength bands. For example, mobilizing optical-atomic clocks for a leap in sensing requires compact lasers at frequencies spread across the visible and near infrared. Integrated

Photonic Millimeter-wave Generation Beyond the Cavity Thermal Limit

February 11, 2025
Author(s)
William Groman, Igor Kudelin, Takuma Nakamura, Yifan Liu, Charles McLemore, Franklyn Quinlan, Scott Diddams, Dahyeon Lee, Megan Kelleher, Joel Guo, Warren Jin, John Bowers
With the next generation of telecommunications and radar/navigation upon us, moving from the microwave to the higher bandwidth, millimeter-wave domain has become ever relevant. Simultaneously, the burgeoning field of photonic integrated chips has yielded a

The bandgap-detuned excitation regime in photonic-crystal resonators

February 11, 2025
Author(s)
Yan Jin, Erwan Lucas, Jizhao Zang, Travis Briles, Ivan Dickson, David Carlson, Scott Papp
Control of nonlinear interactions in microresonators enhances access to classical and quantum field states across nearly limitless bandwidth. A recent innovation has been to leverage coherent scattering of the intraresonator pump as a control of group