Black hole-like quantum encryptors discovered

The scientists used a mathematical tool called out-of-time-order correlators, or OTOCs, which are considered a measure of quantum chaos. OTOCs were invented 55 years ago to calculate how electrons in superconductors are affected by disturbances caused by impurities. This influence is similar to the “butterfly flapping effect” that mathematician Edward Lorenz used to illustrate chaos in atmospheric systems. OTOC allows us to estimate how quickly a quantum system ceases to be predictable with the slightest deviation from its previous trajectory.

In the 1990s, OTOCs were used to model what happens to information falling into a black hole. It is believed that black holes are ideal encryptors, since all information entering them is uniformly washed out along the event horizon, existing in the form of minor surface fluctuations. The same thing happens in the case of chemical reactions: information regarding the quantum states of the reactants is encoded in how the reaction proceeds and affects its speed.

New work has shown that encrypting information in certain types of reactions can be almost as fast as in a black hole. In classical mechanics, a particle must have enough energy to overcome an energy barrier and start a reaction. However, quantum mechanics allows for the possibility of a particle tunneling through a barrier even if it does not have sufficient energy. The OTOC calculation showed that chemical reactions with low activation energy at low temperatures, in which tunneling dominates, encrypt information at the same extreme speed as in a black hole.

Large environments in which chemical reactions occur suppress this effect. This has implications for the creation of reliable quantum computers, in which it is necessary to minimize the encryption of information between interacting tunnel systems.