A team of scientists from the University of Vienna has succeeded in reversing the direction of time in quantum systems, as published in the journal Optics. The experiment was based on the “universal rewind protocol” and involved reversing the changes of a single photon. The team used ultrafast fiber-optic components and free-space interferometers in a complex optical setup to achieve this.
Surprisingly, the experimenter did not need to know any details about the target quantum system to perform the rewind, and the protocol can achieve an arbitrarily high probability of success. The experiment suggests that it is possible to reverse the time evolution of a photon without knowing how it had changed over time or what its initial and final states were, which defies one of the basic tenets of quantum physics that simply observing a system causes it to change. This breakthrough could have applications in improving the efficiency of quantum systems and in error correction.
This discovery is an important step in research on time and quantum mechanics and could have important applications in cryptography and quantum computing. In addition, time reversal in quantum systems could have important practical applications in areas such as quantum computing and cryptography. In particular, the universal rewinding protocol could be used to undo errors in quantum processes and unravel information encoded in quantum states.