Atomic Physics Seminars This Term

ics Atomic
Monday, January 7, 2019
3:30 PM
Physics Building, Room 204
Dr. Gabriel Bie Alves [Host: Olivier Pfister]
Universidade Federal Fluminense, Brazil
"Conditions for optical parametric oscillation with a structured light pump"
ABSTRACT:

We investigate the transverse mode structure of the down-converted beams generated by a type-II optical parametric oscillator (OPO) driven by a structured pump. Our analysis focus on the selection rules imposed by the spatial overlap between the transverse modes of the three fields involved in the non-linear interaction. These rules imply a hierarchy of oscillation thresholds that determine the possible transverse modes generated by the OPO, as remarkably confirmed with experimental results.

ics Atomic
Monday, January 14, 2019
3:30 PM
Physics Building, Room 204
RESERVED
ics Atomic
Monday, January 21, 2019
3:30 PM
Physics Building, Room 204
Ali Azarm [Host: Bob Jones]
University of Arizona
"Ultrafast intense laser interaction with molecules and nanostructures"
ABSTRACT:

Strong laser field interaction with materials is rich in physics and chemistry, and gives rise to variety of spectacular phenomena ranging from multiphoton/tunneling ionization to high harmonics generation. In this talk, I will present three of these intriguing phenomena that I have investigated.

First, I will explain neutral dissociation of hydrogen molecule in strong laser field through multiphoton super-excitation. I will demonstrate the experimental results of fragmentation of hydrogen molecules in a strong laser field including observation of Balmer lines from hydrogen atoms and measuring the upper limit of the lifetime of the super-excited states by an ultrafast pump and probe experiment [1].

The second part of the talk is dedicated to optical gain and population inversion in ions at 428 nm wavelength through high-resolution spectroscopy. I will clarify how sufficient dissimilarity of rotational distributions in the upper and lower emission levels could lead to gain without net electronic or vibronic population inversion [2].

Finally, at the third part of the talk, I will show the results of use of femtosecond laser pulses to melt indium semi-spherical nanostructure (r~175 nm) and shape them by high spatial frequency laser induced periodic surface structures into linear microstructures of 2 μm long in the direction of laser polarization. The understanding of the modification process, melting and moving in the nano-grating structured field, pave the way to design nanostructures of arbitrary shapes at the sub-wavelength scale [3].

[1] A. Azarm, D. Song, K. Liu et al. J. Phys. B: At. Mol. Opt. Phys. 44 (2011) 085601

[2] A. Azarm, P. Corkum, P. Polynkin, Phys. Rev. A Rapid Comm. 96 (2017) 051401(R)

[3] A. Azarm, F. Akhoundi, R. A. Norwood et al. Appl. Phys. Lett. 113 (2018) 033103

ics Atomic
Monday, January 28, 2019
3:30 PM
Physics Building, Room 204
Elizabeth Goldschmidt [Host: Peter Schauss]
US Army Research Laboratory
"Rare-earth atoms in solids as a platform for quantum networks "
ABSTRACT:

I will give an overview of the emerging field of rare-earth atoms in solids as the basis for a variety of quantum information applications. These systems have a number of advantageous properties including long inherent coherence times, lack of motional dephasing or substantial spectral diffusion, and high density, that make them promising systems for important quantum information tasks, such as long-lived, efficient photonic quantum memory. A major challenge associated with most atom-like quantum emitters in solids, rare-earth atoms included, is the inhomogeneous broadening of the optical transition energy caused by site-to-site variation in the local environment. I will discuss initial experimental results on the effect of this broadening on electromagnetically induced transparency in a europium doped sample. Finally I will present our plans and ongoing work to mitigate the effects of inhomogeneity by investigating a new class of materials.

ics Atomic
Monday, February 4, 2019
3:30 PM
Physics Building, Room 204
RESERVED
ics Atomic
Monday, February 11, 2019
3:30 PM
Physics Building, Room 204
Available
ics Atomic
Monday, February 18, 2019
3:30 PM
Physics Building, Room 204
Eddie Moan [Host: Cass Sackett]
University of Virginia - Physics
"A large-area Sagnac interferometer using atoms in a time-orbiting potential"
ABSTRACT:

We describe the implementation of a dual Sagnac interferometer using a Bose-Einstein condensate confined in a harmonic time-orbiting potential magnetic trap, which is sensitive to rotations on the order of Earth’s rate.  Atoms are manipulated using Bragg laser beams to produce two reciprocal interferometers, providing common-mode rejection of accelerations, trap fluctuations, and other noise sources. The Sagnac rotation phase is differential between the two interferometers. The orbit of the atoms is nearly circular, with an effective Sagnac area of about 0.5 mm^2.  This technique has potential applications in terrestrial and space-based inertial navigation systems, which currently use more unstable and less rotation-sensitive optical gyroscopes.

ics Atomic
Monday, February 25, 2019
3:30 PM
Physics Building, Room 204
RESERVED
ics Atomic
Monday, March 4, 2019
3:30 PM
Physics Building, Room 204
Ariel Sommer [Host: Peter Schauss]
Lehigh University
"TBA"
ics Atomic
Monday, March 18, 2019
3:30 PM
Physics Building, Room 204
RESERVED
ics Atomic
Monday, March 25, 2019
3:30 PM
Physics Building, Room 204

"Available"
ics Atomic
Monday, April 1, 2019
3:30 PM
Physics Building, Room 204
Seth Berl [Host: Peter Schauss]
University of Virginia - Physics
"Available"
ics Atomic
Monday, April 8, 2019
3:30 PM
Physics Building, Room 204

"Available"
ics Atomic
Monday, April 15, 2019
3:30 PM
Physics Building, Room 204
RESERVED
ics Atomic
Monday, April 22, 2019
3:30 PM
Physics Building, Room 204

"Available"
ics Atomic
Monday, April 29, 2019
3:30 PM
Physics Building, Room 204
Chun-Hung Chang [Host: Olivier Pfister]
University of Virginia
"Available"

To add a speaker, send an email to ps5nw@Virginia.EDU Include the seminar type (e.g. Atomic Physics Seminars), date, name of the speaker, title of talk, and an abstract (if available). [Please send a copy of the email to phys-speakers@Virginia.EDU.]