Chiral Plasmonic Surface Temperature Switching by Several Tens of Kelvins in Titanium Nitride Nanostructures

TL;DR

This paper shows that titanium nitride nanostructures can create large temperature differences when exposed to different polarized light, enabling control of nanoscale chemical reactions.

Contribution

The study demonstrates temperature switching of tens of kelvins in chiral plasmonic nanostructures using low thermal conductivity titanium nitride.

Findings

Titanium nitride nanostructures show distinct temperature patterns under right- and left-circularly polarized light.

Temperature contrast reaches several tens of kelvins due to low thermal conductivity of titanium nitride.

This effect enables spatial control of photothermal reactions at the nanoscale.

Abstract

The strong asymmetric
optical response of plasmonic metal
nanostructures
to right- and left-handed circularly polarized light has attracted
great interest in nanotechnology. However, when considering heat generation
in these structures, the surface temperature distribution becomes
nearly isothermal regardless of which handedness of circularly polarized
light is used. This is because of the high thermal conductivity of
noble metals and the diffusive nature of heat transfer. In this study,
we experimentally show that the surface temperature patterns of chiral
plasmonic nanostructures made from titanium nitride, which has a thermal
conductivity less than 10% that of gold, become clearly different
under right- and left-circularly polarized light, with the temperature
contrast reaching several tens of kelvins. This temperature switching
allows nanoscale spatial control of photothermal chemical reactions.
Our findings suggest a significant potential for shaping nanoscale
temperature distributions in the field of thermoplasmonics.

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