Alice falls into a black hole: Acceleration and quantum entanglement

Aug 13, 2005

Consider that Alice and Bob are two observers at rest separated by a long distance. Each of them has a measuring device that detects, respectively, two different quantum systems. The state of the joint system is said to be maximally entangled if, for many copies of the state, any measurement that Alice makes is completely determined by Bob's and vice versa.

This upcoming publication by I. Fuentes-Schuller and R. B. Mann will appear in Physical Review Letters.

What would happen to their entanglement if Alice fell into a black hole and Bob stayed safely outside? We can model this situation by considering Alice to be stationary and Rob (formerly Bob) to be uniformly accelerated with respect to Alice. We found that although the entanglement between them is reduced due to Rob's acceleration, it remains nonzero as long as Rob's acceleration is not infinite.

It has long been known that an accelerated observer detects a thermal bath of particles whereas an observer at rest sees only a vacuum. Known as the Unruh effect, it is this that causes the degradation in the entanglement measured by Alice and Rob. Our results are a first step in understanding how relativistic effects modify quantum information, and they imply that different observers detect different degrees of entanglement.

This has important consequences in quantum teleportation between relatively accelerated parties, since entanglement is the main resource in this task.

The abstract
Two observers determine the entanglement between two free bosonic modes by each detecting one of the modes and observing the correlations between their measurements. We show that a state which is maximally entangled in an inertial frame becomes less entangled if the observers are relatively accelerated. This phenomenon, which is a consequence of the Unruh effect, shows that entanglement is an observer-dependent quantity in non-inertial frames. In the high acceleration limit, our results can be applied to a non-accelerated observer falling into a black hole while the accelerated one barely escapes. If the observer escapes with infinite acceleration, the state's distillable entanglement vanishes.

More information on Perimeter may be found on-line at .

Source: Perimeter Institute for Theoretical Physics

Explore further: Physicists precisely measure interaction between atoms and carbon surfaces

Related Stories

Q&A: Why are antibiotics used in livestock?

10 hours ago

Wal-Mart, the world's biggest retailer, is the latest company to ask its suppliers to curb the use of antibiotics in farm animals. Here's a rundown of what's driving the decision: ...

Recommended for you

Self-replicating nanostructures made from DNA

May 28, 2015

(—Is it possible to engineer self-replicating nanomaterials? It could be if we borrow nature's building blocks. DNA is a self-replicating molecule where its component parts, nucleotides, have specific ...

Could computers reach light speed?

May 28, 2015

Light waves trapped on a metal's surface travel nearly as fast as light through the air, and new research at Pacific Northwest National Laboratory shows these waves, called surface plasmons, travel far enough ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.