Two-way communication is possible with a single quantum particle
Studies show two people can simultaneously swap information using only one photon
DOUBLE DUTY Thanks to the phenomenon of quantum superposition, a single particle of light can send information in two directions at once, scientists report.
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Communication is a two-way street. Thanks to quantum mechanics, that adage applies even if you’ve got only one particle to transmit messages with.
Using a single photon, or particle of light, two people can simultaneously send information to one another, scientists report in a new pair of papers. The feat relies on a quirk of quantum mechanics — superposition, the phenomenon through which particles can effectively occupy two places at once.
Sending information via quantum particles is a popular research subject, thanks to the promise of unhackable quantum communication (SN: 12/23/17, p. 27). The new studies specify a previously unidentified twist on that type of technique. “Sometimes you overlook a cool idea, and then it's just literally right in front of your nose,” says University of Vienna experimental physicist Philip
