Quantum entanglement speed is measured for the first time

Key Points:

• Researchers from TU Wien and a Chinese team have successfully measured the formation of quantum entanglement on attosecond timescales, revealing how two particles become interconnected in less than a trillionth of a second.
• Using intense laser pulses to excite electrons in atoms, the team observed that one electron leaves the atom while another changes energy state, resulting in the two electrons becoming quantum entangled and sharing linked properties.
• The timing of the electron's departure is inherently uncertain and exists in a quantum superposition, with the energy state of the remaining electron influencing the average delay of about 232 attoseconds.
• This breakthrough measurement technique, combining two laser beams, allows scientists to capture ultrafast entanglement events, opening new pathways to control quantum systems and enhance technologies like quantum computing and cryptography.
• The findings, published in Physical Review Letters, mark a significant step toward understanding the inception of entanglement, with ongoing collaborations aimed at experimentally verifying these ultrafast quantum phenomena.