Physicists quantify temperature changes in metal nanowires

Jan 17, 2014

( —Using the interaction between light and charge fluctuations in metal nanostuctures called plasmons, a University of Arkansas physicist and his collaborators have demonstrated the capability of measuring temperature changes in very small 3-D regions of space.

Plasmons can be thought of as waves of electrons in a metal surface, said Joseph B. Herzog, visiting assistant professor of physics, who co-authored a paper detailing the findings that was published Jan. 1 by the journal Nano Letters, a publication of the American Chemical Society.

The paper, titled "Thermoplasmonics: Quantifying Plasmonic Heating in Single Nanowires, was co-written by Rice University researchers Mark W. Knight and Douglas Natelson.

In the experiments, Herzog, who joined the U of A faculty last summer, fabricated plasmonic nanostructures with and precisely focused a laser on to a gold nanowire with a scanning optical setup.

"This work measures the change in electrical resistance of a single gold nanowire while it is illuminated with ," Herzog said. "The change in resistance is related to the of the nanowire. Being able to measure temperature changes at small nanoscale volumes can be difficult, and determining what portion of this change is due to plasmons can be even more challenging.

"By varying the polarization of the light incident on the nanostructures, the plasmonic contribution of the optical heating has been determined and confirmed with computational modeling," he said.

Herzog's publication is in a rapidly growing, specialized area called thermoplasmonics, a sub-field of that studies the effects of heat due to plasmons and has been used in applications ranging from cancer treatment to solar energy harvesting.

Herzog combines his research of plasmons with his expertise in nano-optics, which is the nanoscale study of light.

"It's a growing field," he said. "Nano-optics and plasmonics allow you to focus light into smaller regions that are below the diffraction limit of light. A plasmonic nanostructure is like an optical antenna. The plasmon-light interaction makes plasmonics fascinating."

Herzog is setting up his research lab at the University of Arkansas, which will focus on nano-optics and plasmonics. In addition to his appointment in physics, Herzog collaborates with the university's microelectronics-photonics program is a faculty member and the University of Arkansas' Institute for Nanoscience and Engineering.

Explore further: Controlling light with light

More information: "Thermoplasmonics: Quantifying Plasmonic Heating in Single Nanowires." Joseph B. Herzog, Mark W. Knight, and Douglas Natelson. Nano Lett. (2014). DOI: 10.1021/nl403510u

Related Stories

A breakthrough in plasmonics

Jun 17, 2013

EPFL scientists have discovered how optical signal transmission can be controlled, paving the way for the integration of plasmonics with conventional electronic circuits.

Controlling light with light

Jan 10, 2014

A new approach to control light with light without the need for optical nonlinearity: Nanoparticle auto-oscillations in a subwavelength plasmonic V-groove waveguide induced by a control light can be used for the periodic ...

Nanoplasmonics: Towards efficient light harvesting

Jan 07, 2014

The control of light is vital to many applications, including imaging, communications, sensing, cancer treatment, and even welding processes for automobile parts. Transformation optics is an emerging field that has revolutionized ...

Recommended for you

For electronics beyond silicon, a new contender emerges

Sep 16, 2014

Silicon has few serious competitors as the material of choice in the electronics industry. Yet transistors, the switchable valves that control the flow of electrons in a circuit, cannot simply keep shrinking ...

Making quantum dots glow brighter

Sep 16, 2014

Researchers from the University of Alabama in Huntsville and the University of Oklahoma have found a new way to control the properties of quantum dots, those tiny chunks of semiconductor material that glow ...

The future face of molecular electronics

Sep 16, 2014

The emerging field of molecular electronics could take our definition of portable to the next level, enabling the construction of tiny circuits from molecular components. In these highly efficient devices, ...

Study sheds new light on why batteries go bad

Sep 14, 2014

A comprehensive look at how tiny particles in a lithium ion battery electrode behave shows that rapid-charging the battery and using it to do high-power, rapidly draining work may not be as damaging as researchers ...

User comments : 0