Researchers Measured The Speed Of Quantum Entanglement For The First Time Ever, And It Comes Down To Attoseconds

Story by Emily Chan. November 20, 2024.

  • Quantum Events in Slow Motion: Researchers have developed computer simulations to observe quantum events occurring in attoseconds, revealing the dynamics of quantum entanglement.
  • Quantum Entanglement: Using ultraviolet laser pulses and infrared light, scientists studied electron behavior in helium atoms, showing how entanglement occurs when one electron is hit and another jumps to a higher energy state.
  • Attosecond Streaking: This technique tracks the quantum effect between electrons, showing that the birth time of an escaping electron is uncertain, existing in a quantum state at both earlier and later times.
  • Future Applications: Understanding these quantum processes could advance quantum computing and cryptography, enhancing control and utilization of quantum effects.

Some events happen too fast to be captured in a photograph, no matter how quickly you hit the camera button.

For example, certain quantum events are considered to be instantaneous, so they’re hard to observe. But now, it has become possible to watch such occurrences unfold in slow motion.

A team of researchers has created computer simulations capable of tracking quantum events that take place in mere attoseconds, which are billionths of a billionth of a second.

“You could say that the particles have no individual properties, they only have common properties. From a mathematical point of view, they belong firmly together, even if they are in two completely different places,” said Joachim Burgdörfer from the Vienna University of Technology.

The research team consists of scientists from Austria and China. They used powerful ultraviolet laser pulses and infrared light to assess electron behavior when they’re torn from helium atoms, revealing the birth of quantum entanglement, one of nature’s fastest moments.

When one electron is hit with just the right amount of intense light, it will get torn away from the atom while another electron remains behind but jumps to a higher state of energy.

As a result, the two electrons become quantum entangled, and one cannot be described without the other.

The researchers also used computer simulations to track the quantum effect between the escaping electron and the remaining one. The technique is referred to as “attosecond streaking,” and it works like a super accurate stopwatch.

They discovered that the birth time of the electron that flies away is technically unknown. It simultaneously exists in a quantum state where it departs at both an earlier and later time-on average, about 232 attoseconds apart.

“The electron doesn’t just jump out of the atom. It is a wave that spills out of the atom, so to speak-and that takes a certain amount of time,” said Iva Březinová, a professor and co-author of the study.

“It is precisely during this phase that the entanglement occurs, the effect of which can then be precisely measured later by observing the two electrons.”

The current study relies on computer simulations and models, but the researchers are already making plans to prove these quantum entanglements in real-life settings.

Soon, technology will be advanced enough to generate light pulses that are sufficiently accurate to take such measurements.

Overall, the research illustrates that quantum processes do not actually occur instantaneously. They unfold over very brief periods of time.

Learning more about these dynamics could lead to progress in areas such as quantum computing and cryptography, changing the game for the control and utilization of quantum effects.