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.
Loren F. Goodrich, Najib Cheggour, Theodore C. Stauffer, James Filla, Xifeng Lu
We review variable-temperature, transport critical-current (Ic) measurements made on commercial superconductors over a range of critical currents from less than 0.1 A to about 1 kA. We have developed & used a number of systems to make these measurements
David L. Miller, Mark W. Keller, Justin Shaw, Katherine P. Rice, Robert Keller, Kyle M. Diederichsen
Single crystal metal films on insulating substrates are attractive for microelectronics and other applications, but they are difficult to achieve on macroscopic length scales. The conventional approach to obtaining such films is epitaxial growth at high
Burm Baek, Samuel P. Benz, William H. Rippard, Stephen E. Russek, Paul D. Dresselhaus, Horst Rogalla, Matthew R. Pufall
If Josephson and spintronic technologies can be successfully integrated to produce a cryogenic memory that can be controlled with single-flux quantum pulses, then they may enable ultra-low-power, high-speed computing. We have developed hybrid Josephson
Kevin J. Dwyer, Joshua M. Pomeroy, David S. Simons
A mass selected ion beam system is used to isotopically enrich and deposit thin films, which are measured to be 99.9961(4)% 12C. In solid state quantum information, isotopic enrichment of materials has allowed significant improvements in the coherence time
Robert W. Carpick, Rachel J. Cannara, Ashlie Martini
Atomic level stick-slip refers to the behavior of a sliding interface, usually an atomic force microscope tip sliding along a crystalline surface, whereby the tip sticks and then slips laterally with respect to the surface in a periodic fashion. The
We describe a new method for creating spin-dependent long-range interactions between atomic ultra-cold neutral bosons in an optical lattice. In this proposal, the bosonic system is immersed in a spin polarized degenerate Fermi gas. We first show that the
Antia A. Lamas-Linares, Brice R. Calkins, Nathan A. Tomlin, Thomas Gerrits, Adriana Lita, Joern Beyer, Richard Mirin, Sae Woo Nam
Transition edge sensors (TES) have the highest reported efficiencies (> 98%) for single photon detection in the visible and near infrared. Experiments in quantum information and foundations of physics that rely on this efficiency have started incorporating
Mariano A. Real, Eric Lass, Fan-Hung H. Liu, Tian T. Shen, George R. Jones Jr., Johannes A. Soons, David B. Newell, Albert Davydov, Randolph Elmquist
A well-controlled technique for high-temperature epitaxial growth on 6H-SiC(0001) substrates is shown to allow development of monolayer graphene that exhibits promise for precise metrological applications. Face-to-face (FTF) and face-to-graphite (FTG)
Logan A. Howe, Charles J. Burroughs, Paul D. Dresselhaus, Samuel P. Benz, Robert E. Schwall
Given the recent shortages of liquid helium, cryogen-free operation of superconducting devices such as programmable Josephson voltage standard (PJVS) systems has become preferred worldwide, and a necessity in some locations. Besides consistent and accurate
Thomas P. Forbes, Timothy M. Brewer, John G. Gillen
We present the investigation of droplet charging and charge transmission characteristics of an electro-flow focusing nozzle for desorption-based ambient ionization mass spectrometry. The electro-flow focusing geometry utilizes a concentrically flowing gas
We present a general theoretical framework on light-wave mixing and scattering in quantum gases. We show that all such processes that originate from elementary excitations are stimulated Raman or hyper-Raman in nature. In the forward direction, the third
Justin Shaw, Hans Nembach, Thomas J. Silva, Margaret M. Murnane, Henry C. Kapteyn, Martin Aeschlimann, Claus M. Schneider, Emrah Turgut, Stefan Mathias, Patrik Grychtol, Chan La-O-Vorakiat, Dennis Rudolf, Roman Adam
The study of ultrafast dynamics in magnetic materials provides rich opportunities for greater fundamental understanding of correlated phenomena in solid-state matter, because many of the basic microscopic mechanisms involved are as-yet unclear and are
Carl T. Boone, Hans Nembach, Justin Shaw, Thomas J. Silva
We measured spin-transport in nonferromagnetic (NM) metallic multilayers from the contribution to damping due to spin pumping from a ferromagnetic Co 90Fe 10 thin film. The multilayer stack consisted of NM 1/NM 2/Co 90Fe 10(2 nm)/NM 2/NM 3 with varying NM
Richard A. Perkins, Jan V. Sengers, Ilmutdin M. Abdulagatov, Marcia L. Huber
The available information for the thermal-conductivity enhancement is reviewed. We show that it can be represented by a simplified solution of the mode-coupling theory of critical dynamics with two critical amplitudes and one cutoff wave number as fluid
Peter J. Lowell, Galen C. O'Neil, Jason M. Underwood, Joel N. Ullom
Nano- and Micro- Electromechanical devices (NEMS & MEMS) have become ubiquitous; examples include automobile accelerometers, inkjet printer heads, infrared viewers, and mirrors for image manipulation and projection. Applications fall broadly in the
Martin O. Sandberg, Tomas A. Ohki, Jose A. Aumentado, Martin P. Weides, David P. Pappas
We present a superconducting transmon qubit circuit design based on large, coplanar capacitor plates and a microstrip resonator. The microstrip geometry, with the ground plane on the back, enhances access to the circuit for state preparation and
Daniel C. van der Laan, Patrick D. Noyes, Miller E. George, Hubertus W. Weijers, Willering P. Gerard
The next generation of high-field magnets that will operate at magnetic fields substantially above 20 T, or at temperatures substantially above 4.2 K, requires high-temperature superconductors (HTS). Conductor on round core (CORC) cables, in which RE-Ba
We use broadband ferromagnetic resonance spectroscopy and x-ray diffraction to investigate the fundamental origin of perpendicular anisotropy in Co 90Fe 10/Ni multilayers. By careful evaluation of the spectroscopic g-factor, we determine the orbital moment
Douglas A. Bennett, Daniel S. Swetz, Daniel R. Schmidt, Joel N. Ullom
The transition between the superconducting and normal states is of extreme practical importance because the very sharp onset of resistance in voltage biased thin films is the basis for transition- edge sensors (TESs). TESs are being successfully utilized
Dale Li, Jason Austermann, James A. Beall, Daniel T. Becker, Hsiao-Mei Cho, Anna E. Fox, Nils Halverson, Jason Henning, Gene C. Hilton, Johannes Hubmayr, Jeffrey L. Van Lanen, John P. Nibarger, Michael D. Niemack, Kent D. Irwin
Dielectric loss in low-temperature superconducting integrated circuits can cause lower overall efficiency, particularly in the 90 to 220 GHz regime. We present a method to tune the dielectric loss for silicon oxide deposited by plasma-enhanced chemical
Zhao Z. Deng, Nikolai Klimov, Santiago Solares, Teng Li, Hua Xu, Rachel J. Cannara
Using atomic force microscopy (AFM), we study the adhesive, frictional and elastic properties of supported and suspended graphene exfoliated onto pit-patterned silicon dioxide-on-silicon (SiO2/Si) substrates. In spite of the greater adhesive force between
Stephen E. Russek, Ranko R. Heindl, Thomas Cecil, William H. Rippard
Spin transfer nano-oscillators are small multilayer magnetic devices that undergo microwave oscillations and output a microwave voltage when a bias current is applied. The oscillation frequency is tunable, over a range of 0.5 GHz to 225 GHz, by varying the
Thomas J. Silva, Justin M. Shaw, Hans T. Nembach, Chan La-O-Vorakiat, Henry C. Kapteyn, Margaret M. Murnane, Stefan Mathias, Roman Adam, Patrik Grychtol, Martin Aeschlimann, Claus M. Schneider, Emrah Turgut, Dennis Rudolf
We review recent progress in femtosecond magnetization dynamics probed by extreme ultraviolet pulses from high-harmonic generation. In a transverse magneto-optical Kerr geometry, we establish an ultrafast, element-specific experimental capability - on a
Daniel S. Swetz, Douglas A. Bennett, Daniel R. Schmidt, Joel N. Ullom
Present models of the superconducting-to-normal transition in transition-edge sensors (TESs)do not describe the current distribution within a biased TES. This distribution is complicated by normal-metal features that are integral to TES design. We present
David Bishop, Flavio Pardo, Cris Bolle, Randy Giles, Vladimir Aksyuk
Over the last decade or so a group of us, while working at Bell Labs, have been able to develop a large number of silicon micromachines for a wide range of applications. In this article, which is part of a special volume to celebrate the career of