Physicists demonstrate quantum mechanical nature of heat flow

Apr 15, 2005

One of the hallmarks of quantum mechanics -- the laws of physics that apply on very small scales -- is the wave nature exhibited by sub-atomic particles such as electrons. An electron presented with two paths to a destination will use its wave nature to traverse both paths and, depending on the parameters of the two paths, will constructively or destructively interfere with itself at its destination, leading to a high or low probability of it appearing there.

A classic demonstration of this is the Aharonov-Bohm effect where electrons are sent along two paths that may be altered by the application of an external magnetic field. By tuning the magnetic field, the constructive or destructive interference of the electrons is manifested as an increase or decrease in the conduction of electric current. Now physicists at Northwestern University show that, using the fact that electrons carry heat as well as charge, the conduction of heat may be similarly tuned. Their findings will be published April 22 by Physical Review Letters, the journal of the American Physical Society.

Venkat Chandrasekhar, professor of physics in Northwestern's Weinberg College of Arts and Sciences, and his graduate student Zhigang Jiang showed that a magnetic field can be used to increase or decrease the flow of heat through an "Andreev interferometer," a nanoscale device with one normal metal path and one superconducting path. Though the quantum interference of electrons in this device is responsible for these changes in heat flow, the flow of charge through the interferometer is zero. The researchers recently observed this effect experimentally.

Source: Northwestern University

Explore further: Engineered proteins stick like glue—even in water

add to favorites email to friend print save as pdf

Related Stories

How hostile is space?

Aug 06, 2014

Space may seem calm, but it is a more hostile environment than that on Earth. Invisible radiation is a big problem for space enthusiasts and scientific instruments. Substituting electronic devices to do human ...

How the "biological spark plug" in biomolecular motors works

Aug 04, 2014

Using high-performance computers and quantum mechanical methods, researchers at Heidelberg University have simulated processes that reveal how the "biological spark plug" works in the biomolecular motors of cells. Under the ...

NREL bolsters batteries with nanotubes

Jul 01, 2014

Researchers at the Energy Department's National Renewable Energy Laboratory (NREL) are turning to extremely tiny tubes and rods to boost power and durability in lithium-ion batteries, the energy sources for ...

Recommended for you

Engineered proteins stick like glue—even in water

3 hours ago

Shellfish such as mussels and barnacles secrete very sticky proteins that help them cling to rocks or ship hulls, even underwater. Inspired by these natural adhesives, a team of MIT engineers has designed new materials that ...

Smallest possible diamonds form ultra-thin nanothreads

3 hours ago

For the first time, scientists have discovered how to produce ultra-thin "diamond nanothreads" that promise extraordinary properties, including strength and stiffness greater than that of today's strongest ...

A nanosized hydrogen generator

Sep 20, 2014

(Phys.org) —Researchers at the US Department of Energy's (DOE) Argonne National Laboratory have created a small scale "hydrogen generator" that uses light and a two-dimensional graphene platform to boost ...

User comments : 0