Bulletin of the American Physical Society
APS March Meeting 2023
Volume 68, Number 3
Las Vegas, Nevada (March 5-10)
Virtual (March 20-22); Time Zone: Pacific Time
Session G52: Ultrafast Spectroscopy and Optical Techniques
11:30 AM–2:06 PM,
Tuesday, March 7, 2023
Room: Room 308
Sponsoring
Unit:
DLS
Chair: David Reis, Stanford PULSE Institute
Abstract: G52.00006 : Phonon-Polaritons in Hexagonal Boron Nitride Induced by Evanescent Radiative Coupling*
12:30 PM–12:42 PM
Presenter:
William D Hutchins
(University of Virginia)
Author:
William D Hutchins
(University of Virginia)
As electronic devices continue to reduce towards nanoscale dimensions, un-
derstanding heat transport mechanisms at these scales becomes vital. In most
non-metallic materials heat dissipates according to the movements of phonons
or phonon-like waves. The efficiency of this phonon-mediated heat transport is
dictated by various characteristics of these modes including their lifetime, scat-
tering rate, and velocity. Thus, the high group velocity of phonon-polarions can
facilitate more efficent heat transport in devices. From an experimental perspec-
tive, the majority of recent advances in such characteristics stems from ther-
moreflectance measurements, namely TDTR and FDTR, where phonon trans-
port is inferred from trends in thermal conductivity of materials. In other words,
these methods measure the average temperature of a material following pulsed
excitation rather than directly monitoring the activity of individual modes of
interest. In this work, we use a novel ultrafast pump-probe technique that can
observe specific vibrational modes with sub-picosecond time resolution, thus
characterizing the aforementioned phonon-polariton dynamics.
Our technique relies on a wavelength tunable mid-infrared probe pulse, al-
lowing us to directly resonate with vibrational heat carriers, thus providing
a direct measure of phonon dynamics in nanoscale material systems. In par-
ticular, we investigate the phonon-polariton dynamics in hexagonal boron ni-
tride (h-BN); the high frequency optical modes in this material lend themselves
to the potential for manipulation of thermal radiation in near room temper-
ature conditions. Thus we investigate the ultrafast thermal dynamics of the
transverse optical (TO) modes, the high reflectivity Reststrahlen band, and a
unique regime of polaritonic heat transfer: the generation of a thermal radiation-
induced phonon polariton. For the first time, we experimentally demonstrate
the ability to stimulate phonon polaritons in h-BN through remote heating of a
metal contact. Our results open the door for future experiments to manipulate
and guide phonons via heterostructures, which could increase thermal efficiency
of microelectronics and photonics.
*Army Research Office
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700