Our concept of reality may be more fragile than we think: a team of scientists from Nanjing University in China has used a trick called “pseudo-quantum telepathy,” under which reality does not exist in a fixed state until it is measured. And it is that, as quantum physics explains, things are not necessarily there if they are not looked at.
To illustrate this point, physicists devised a series of theoretical matching games in which two players have a limited chance of winning as long as they cannot communicate with each other—if the measurements merely reveal reality as it exists—but they can be systematically conquered using pseudo-quantum telepathy. In other words, both players, if they take advantage of quantum effects, can always win.
The idea that physical objects can exist in multiple states simultaneously—and in two mutually exclusive conditions at once—is known as wave-particle duality (also called wave-particle duality). For example, as explained Sciencea photon can be polarized so that the electric field it contains is twisted vertically, horizontally, or both ways at the same time, at least until it is measured.
At that time, the bidirectional state is randomly reduced to vertical or horizontal. The most important thing is that, regardless of how the bidirectional state collapses, an observer cannot assume that the measurement is limited to revealing how the photon was already polarized. The polarization only appears with the measurement.
Thus, two photons can be entangled so that each is in an uncertain state in both directions, but their polarizations are correlated so that if one is horizontal the other must be vertical and vice versa.
The ability to extract a concrete reality from the quantum aether in this way thus raises the possibility of overcoming the limitations of classical statistics. In the case of the game, players equipped with a certain quantum resource can achieve better performance than those with the classics.
Mermin-Peres magic square
To prove their point, Xi-Lin Wang and Hui-Tian Wang, physicists at Nanjing University, and their colleagues used a long-established experiment, the Mermin-Peres magic square game, in which two players “conspire ” to measure photons.
Hypothetical players named Alice and Bob make independent measurements of the photons and record their results on a 3X3 grid with either a “1” or a “-1”. After recording the values, a hypothetical judge arrives and randomly selects one of Alice’s rows and one of Bob’s columns. If both players have the same number in the overlapping box, they win.
To prevent Alice and Bob from fixing the game by agreeing to write the same number in all the boxes, the rules require “parity”, requiring that all entries in Alice’s row be multiplied by 1 and Bob’s column be multiplied by 1. are multiplied by -1. Most important of all, the two players cannot talk to each other during the game.
Statistically impossible to win every time
When playing such a game in the real world, the two players’ nine-square grids must differ by at least one square, meaning that it is statistically impossible to win more than eight times in nine rounds. However, in the quantum world, Alice and Bob can always win.
This is because quantum mechanics removes the need for each box to contain a fixed value before the round is played, allowing a “1” or “-1” to come up only once the arbiter has made a selection. ; interleaving thus ensures that they agree on the key cell number and that their measurements also obey the parity rules.
In other words, the whole scheme works because the values arise only when the measurements are made: the measurements are actually causing the results and not the other way around. The rest of the grid is irrelevant, since the values don’t exist for measurements that Alice and Bob never take.
Win rate exceeds classic stat
As reported Science, such a game cannot be played with paper and ink, but can be demonstrated using entangled quantum particles. To do this, the experimenters used ultrafast laser pulses to excite barium borate crystals, generating pairs of photons that are entangled in two directions.
More specifically, the photons became entangled in such a way that the polarization of one of them was intrinsically linked to the orbital angular momentum of the other, which determines whether a wave photon drifts to the right or to the left.
Using these values as proxies for player numbers, Alice and Bob won 93.84% of 1,075,930 rounds, beating the maximum of 88.89% with hidden variables, the team reports in a study in press at Physical Review Letters.
While not perfect, the 93.84% win rate is above what should be possible according to classical statistics, proving that physical reality is not fixed and can be manipulated through quantum entanglement. Quantum advantage through “pseudotelepathy”. A difficult “reality” to digest?
Edited by Felipe Espinosa Wang.