Researchers have demonstrated that time travel is possible – although only by one particle for a tiny fraction of a second.
Using an IBM 5-qubit quantum computer and a time-travel algorithm, the team was able to reverse the age of a particle by a millionth of a second.
Although the particle didn’t actually travel back in time, the experiment simulated its progression and reversal through time.
This type of aging and de-aging is unlikely to occur in nature. However, using a quantum computer allows scientists to manipulate quantum states to achieve time reversal.
To perform the experiment, qubits in IBM’s quantum computer were set up to function as the particle. Simplistically speaking, they were bombarded with microwaves to shift them to a more complex state, at which point they were frozen. Microwaving them again caused them to regress by a millionth of a second.
You can read the research paper here