Electricity can run between two superconductors
even through electrically insulating barriers
(yellow). Now researchers have found that a
magnetic field (curved arrowa) can switch the
amount of heat that flows from a hot side (red)
to a cold one (blue).


Magnetism flips heat flow

Validation of long-predicted quantum effect points the way to thermal electronics.

Edwin Cartlidge
19 December 2012

The strange world of quantum mechanics just got a little stranger with the discovery that a magnetic field can control the flow of heat from from one body to another. First predicted nearly 50 years ago, the effect might some day form the basis of a new generation of electronic devices that use heat rather than charge as the information carrier.

The research stems from the work of physicist Brian Josephson, who in 1962 predicted1 that electrons could ‘tunnel’ between two superconductors separated by a thin layer of insulator — a process forbidden in classical physics. The Josephson junction was subsequently built and used to make superconducting quantum interference devices (SQUIDs), which are now sold commercially as ultra-sensitive magnetometers.

Read more: Magnetism flips heat flow : Nature News & Comment.

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