Ying-Ju Wang (Fed)

Ying-Ju Wang is a physicist in the Atomic Devices and Instrumentation Group at the National Institute of Standards and Technology. Her current research focuses on the development of miniaturized atomic sensing devices such as atomic magnetometers for a wide range of application including biomedical, geoscience, to space explorations, etc. She received her B.S. in Physics and M.S. in EE from National Taiwan University in 1996 and 1998 as well as her Ph.D. degree in Physics from University of Colorado at Boulder.

Publications

Gradient Field Detection Using Interference of Stimulated Microwave Optical Sidebands
APRIL 21, 2022
AUTHOR(S):
KALEB CAMPBELL, YING-JU WANG, IGOR SAVUKOV, PETER D. D. SCHWINDT, YUAN-YU JAU, AND VISHAL SHAH

We demonstrate that stimulated microwave optical sideband generation using parametric frequency conversion can be utilized as a powerful technique for coherent state detection in atomic physics experiments.

Non-mechanical beam steering in the mid-wave infrared
May 11, 2017
AUTHOR(S):
JESSE A. FRANTZ, JASON D. MYERS, ROBEL Y. BEKELE, CHRISTOPHER M. SPILLMANN, JAWAD NACIRI, JAKUB S. KOLACZ, HENRY GOTJEN, LESLIE B. SHAW, JASBINDER S. SANGHERA, BENNETT SODERGREN, YING-JU WANG, SCOTT D. ROMEEL, MIKE ANDERSON, SCOTT R. DAVIS, AND MICHAEL ZIEMKIEWICA

The mid-wave infrared (MWIR) portion of the electromagnetic spectrum is critically important for a variety of applications such as LIDAR and chemical sensing. Concerning the latter, the MWIR is often referred to as the “molecular fingerprint” region owing to the fact that many molecules display distinctive vibrational absorptions in this region, making it useful for gas detection.

Sensitivity Comparison of Mx and Frequency-Modulated Bell–Bloom Cs Magnetometers in a Microfabricated Cell
September 18, 2009
AUTHOR(S):
RICARDO JIMENEZ-MARTINEZ, CLARK W. GRIFFITH,  YING-JU WANG, SVENJA KANPPE, JOHN KITCHING, KEN SMITH, AND MARK D. PROUTY

We compare the sensitivity performance of two optically pumped atomic magnetometers based on the Mx and frequency-modulated bell-bloom configurations. The Cs magnetometers are implemented using a millimeter-scale microfabricated vapor cell. It is found that the Bell-Bloom magnetometer yields sensitivities similar to those of the Mx magnetometer when operated under equally optimized conditions.

Magnetic resonances in atomic vapor excited by a mechanical resonator
December 1, 2006
AUTHOR(S):
YING-JU WANG, MATT EARDLEY, SVENJA A. KNAPPE, JOHN MORELAND, LEO W. HOLLBERG, JOHN E. KITCHING

We demonstrate a direct resonant interaction between the mechanical motion of a mesoscopic resonator and the spin degree of freedom of a sample of neutral atoms in the gas phase. This coupling, mediated by a magnetic particle attached to the tip of the resonator, allows the excitation of the atomic spin precession about a static magnetic field. The novel coupled atom-resonator system may enable development of low-power, high performance sensors as well as cold atom manipulation, quantum computation, and high-resolution microscopy.

Atom Michelson Interferometer on a Chip Using a Bose-Einstein Condensate
March 11, 2005
AUTHOR(S):
YING-JU WANG, DANAN Z. ANDERSON, VICTOR M. BRIGHT, ERIC A. CORNELL, QUENTIN DIOT, TETSUO KISHIMOTO, MARA PRENTISS, R. A. SARAVANAN, STEPHEN R. SEGAL, AND SAIJUN WU

An atom Michelson interferometer is implemented on an “atom chip.” The chip uses lithographically patterned conductors and external magnetic fields to produce and guide a Bose-Einstein condensate. Splitting, reflecting, and recombining of condensate atoms are achieved by a standing-wave light field having a wave vector aligned along the atom waveguide. A differential phase shift between the two arms of the interferometer is introduced by either a magnetic-field gradient or with an initial condensate velocity. Interference contrast is still observable at 20% with an atom propagation time of 10 ms.

Splitting matter waves using an optimized standing-wave light-pulse sequence
April 6, 2005
AUTHOR(S):
SAIJUN WU, YING-JU WANG, QUENTIN DIOR, AND MARA PRENTISS

In a recent experiment (Wang et al., e-print cond-mat/0407689), it was observed that a sequence of two standing-wave square pulses can split a Bose-Einstein Condensate at rest into ±2ℏk diffraction orders with almost 100% efficiency. By truncating the Raman-Nath equations to a two-state model, we provide an intuitive picture that explains this double-square-pulse beam-splitter scheme. We further show it is possible to optimize a standing-wave multiple-square-pulse sequence to efficiently diffract an atom at rest to a symmetric superposition of ±2nℏk diffraction orders with n>1. The approach is considered to be qualitatively different from the traditional light-pulse schemes in the Bragg or the Raman-Nath region, and can be extended to more complex atomic optical elements that produce various tailored output momentum states from a cold atom source.

Efficient loading of a magnetic waveguide on an atom chip
August 18, 2005
AUTHOR(S):
PETER D. D. SCHWINDT, ERIC A. CORNELL, TETSUO KISHIMOTO, YING-JU WANG, AND DANA Z. ANDERSON

We demonstrate efficient loading of neutral atoms into a magnetic waveguide produced by the magnetic fields of microfabricated current-carrying conductors. The lithographically patterned conductors on this “atom chip” can be used to make a variety of guiding and trapping structures for manipulating cold atoms and Bose-Einstein condensates. A three-chamber vacuum apparatus collects atoms in a magneto-optical trap, precools them via evaporative cooling, and delivers them to the final chamber containing the atom chip. We describe in detail how the precooled atomic cloud is transferred from a macroscopic magnetic Ioffe-Pritchard trap to the microscopic magnetic waveguide on the atom chip 21cm away. Permanent magnets provide a confining two-dimensional quadrupole field to guide the atoms between the two chambers while longitudinally the cloud is allowed to freely expand during the transfer. Strategically placed coils are used to control the longitudinal size and speed of the atomic cloud as it is loaded on the atom chip.

Magnetic switch for integrated atom optics
March 15, 2001
AUTHOR(S):
DIRK MULLER, ERIC A. CORNELL, MARCO PREVEDELLI, PETER D. D. SCHWINDT, YING-JU WANG, AND DANA Z. ANDERSON

A magnetic waveguide structure allows switching of neutral atoms between two guides. The switch consists of lithographically patterned current-carrying wires on a sapphire substrate. By selectively sending current through a particular set of wires, we select the desired output port of an incoming beam. We utilize two different magnetic-guiding schemes to adiabatically manipulate the atom trajectory.

Patents (2018 - Present)

WIDEBAND TUNABLE RYDBERGMICROWAVE ELECTROMETER 
NIST INVENTORS: YING-JU WANG
US application No. 63160783

RYDBERG-MOLECULE-BASED MICROWAVE DIRECTION FINDING 
NIST INVENTORS: YING-JU WANG
US application No. 63048302

OPTICAL ILLUMINATOR MODULE AND RELATED TECHNIQUES 
NIST INVENTORS: YING-JU WANG
US application No. 10732265

ATOMIC BIASING AND CLOSE LOOP CONTROL ON AN ATOM INTERFEROMETER 
NIST INVENTORS: YING-JU WANG
US application No. 10444016