If you don't look at the moon, it isn't there. According to quantum mechanics, what you measure matters. Physicists in China have made it clear that proof of reality is like that. They performed a matching game in which two players leverage quantum effects to win every time, but they can't if measurement reveals reality as it is.
According to Adan Cabello, a theoretical physicist at the University of Seville, this is the simplest scenario in which this happens. Anne Broadbent is a quantum information scientist at the University ofOttawa. We are observing something that has no classical equivalents.
A quantum particle can exist in two different conditions at the same time. The electric field in a photon can be divided into vertically, horizontally, or both ways at the same time until it ismeasured. The collapse of the two-way state is random. Even though the two-way state collapses, an observer can't assume the measurement reveals how the photon was already divided. The measurement is the only one that can make a difference.
Albert Einstein thought that a photon should have a value regardless of whether it is measured. Particles might have hidden variables that determine how a two-way state collapses. In 1964, British theorist John Bell found a way to prove that hidden variables can't exist.
If one of the two photons is horizontal and the other is vertical, the other must be vertical. It's difficult to probing entangled objects. Alice and Bob need a measuring apparatus to do that. Alice can use those devices to determine whether her photon is horizontal or vertical, while Bob can't use his detector to determine whether it's horizontal or vertical. The orientation of the detectors has an effect on how much they correlate with one another.
Alice and Bob would orient their detectors randomly and compare their results. The correlations between Alice's and Bob's measurements can only be so strong. He said that quantum theory allowed them to be stronger. Over many trials, the stronger correlations have been ruled out.
The point has been made more clearly through the Mermin-Peres game. Each round of the game, Alice and Bob share two pairs of entangled photons on which to make a measurement. Each player has a three-by-three grid and fills each square in it with a 1 or a -1, depending on the result of the measurement. Each round, a referee selects one of Alice's rows and one of Bob's columns, which overlap in one square. They win the round if they have the same number.
Alice and Bob guaranteed a win by putting 1 in each square. It isn't so fast. All entries in Alice's row must be equal to 1 and those in Bob's column must be equal to 1
Alice and Bob can't win every round if hidden variables are to be believed. A grid already filled out with 1s and 1s is effectively specified by each possible set of values. The measurement results tell Alice which one to choose. It's the same for both of them. There is no single grid that can satisfy both Alice's and Bob's rules. Their grids have to agree in at least one square, and on average, they can win most of the time.
They have quantum mechanics that allow them to win. David Mermin, a theorist at Cornell University, and Asher Peres, a onetime theorist at the Israel Institute of Technology, came up with the set of measurements. The squares in the row specified by the referee and the squares in the column are measured by Alice. It is guaranteed that they agree on the number in the key square. The values emerge as the measurements are made. Values don't exist for measurements that Alice and Bob don't make, so the rest of the grid isn't important.
It's impractical to generate two pairs of entangled photon at the same time. The experimenters used a single pair of photons that were entangled in two different ways to determine whether a wave like photon corkscrews to the right or to the left. The experiment isn't perfect, but Alice and Bob won 93.84% of the time, exceeding the 88.89% maximum with hidden variables.
Cabello says that others have demonstrated the same physics, but they use exactly the language of the game. He says the demonstration could be useful.
Broadbent would like to verify the work of a quantum computer in the real world. A quantum computer is supposed to do things that an ordinary computer can't. Broadbent believes that if the game were woven into a program, it would be possible to confirm that the quantum computer is manipulating states.
The purpose of the experiment was to show the potential of the team's own technology. We want to improve the quality.
All Rights Reserved © 2024
