It is more quantum cryptography than quantum teleportation that has made them the celebrities they have become in their field. But these two ideas emerged in the 1980s as nascent reflections around what would be called quantum computing. While emerging, the Turing Award is often described as the most prestigious award in computer science, it had never before rewarded work linked to quantum physics.
It was in 1984 that Bennett and Brassard developed the first concept of a “quantum encryption key” – a key that the sender of a message would share with their counterpart through a stream of photons. The protocol is now known as BB84 (for Brassard and Bennett). The immense interest for enthusiasts of secret messages lies in the fact that any attempt to intercept the photons would destroy the information contained and would reveal the presence of a “spy” at the same time.
And it was in 1993 that a team of six researchers, including Bennett, Brassard, and the Quebecois Claude Crépeau, described in the journal Physical Review Letters the concept of quantum teleportation. The concept itself is a consequence of the phenomenon called quantum entanglement: two particles are linked in such a way that they must be considered as a unique system, even if they are very far apart. This becomes a way to send information, provided that the sender holds one of these particles and their counterpart holds the other.
However, for Star Trek fans, there is nothing of the “transporter” in this idea. As the text from the “Rumor Detector” this week points out, while “classic” teleportation would require energy and technological challenges beyond comprehension, quantum teleportation can only involve the transfer of information, not matter.
Already last year, a Chinese team transmitted quantum information thousands of kilometers through microsatellites. In the long run, the most optimistic see the emergence of a “quantum Internet” where inviolable data would travel between quantum computers.
The “Rumor Detector” text is part of a series on “quantum myths,” because of the abundance of myths circulating around the word “quantum” is in itself a reminder that these two pioneers have opened up a sector that they themselves could not have imagined, just 40 years ago, would become more than an intellectual game for “nerds.” As Gilles Brassard explains in the journal Nature, at the time, “Charlie and I were just having fun throwing crazy ideas around.”
Gilles Brassard, born in 1955, is a computer science professor at the University of Montreal since the 1980s. He has received several awards, including the Wolf Prize in physics and the Breakthrough Prize in fundamental physics. He is also an officer of the Order of Canada and the National Order of Quebec. Charles H. Bennett, born in 1943, is a physicist at IBM Research in upstate New York since the 1970s. He has also received numerous awards, including the Breakthrough Prize (with Brassard and two other colleagues) and the Wolf Prize (with Brassard).
In its statement, the Association for Computing Machinery, which has been awarding the Turing Award since 1966, praises the two laureates as “playing an essential role in establishing the foundations of quantum computing and transforming secure communications and computing.” Bennett and Brassard’s ideas “have pushed the boundaries of computing” and “today’s global momentum behind quantum technologies testifies to the enduring importance of their contributions.”
The Turing Award comes with a $1 million prize, with financial support from Google. It is named after the British mathematician Alan M. Turing, who laid the mathematical foundations of computing.
