Long-range interactions leave a quantum reminder

September 4, 2017, Joint Quantum Institute
Credit: Joint Quantum Institute

Given enough time, a forgotten cup of coffee will lose its appeal and cool to room temperature. One way of telling this tepid tale involves a stupendous number of coffee molecules colliding like billiard balls with themselves and colder molecules in the air above. Those constant collisions siphon energy away from the coffee, bit by bit, in a process that physicists call thermalization.

But this story doesn't mention , and scientists think that thermalization must ultimately have a precursor at the . Recently, scientists have sketched out some of the ways that small quantum systems thermalize, sometimes even when they are almost completely isolated.

Last week, in Science Advances, a team of researchers from JQI and Indiana University reported finding a new kind of effect on the road to thermalization—one in which a chain of up to 22 trapped ions, all initially with their quantum spins aligned, can retain a memory of a flipped spin long after it begins to roam through the chain.

Unlike previous results in which imperfections trapped such flips near their starting spot, the memory in this experiment comes from the long-range communication of the ions and confirms a theoretical prediction by two of the paper's authors.

Explore further: Researchers observe dynamical quantum phase transitions in an interacting many-body system

More information: Brian Neyenhuis et al. Observation of prethermalization in long-range interacting spin chains, Science Advances (2017). DOI: 10.1126/sciadv.1700672

Related Stories

Atomic cousins team up in early quantum networking node

July 13, 2017

Large-scale quantum computers, which are an active pursuit of many university labs and tech giants, remain years away. But that hasn't stopped some scientists from thinking ahead, to a time when quantum computers might be ...

Flying qubits make for a highly resilient quantum memory

October 31, 2014

(Phys.org) —In a quantum memory, the basic unit of data storage is the qubit. Because a qubit can exist in a superposition state of both "1" and "0" at the same time, it can process much more information than a classical ...

Spin glass physics with trapped ions

May 27, 2016

One of the most striking discoveries of quantum information theory is the existence of problems that can be solved in a more efficient way with quantum resources than with any known classical algorithm.

Recommended for you

How community structure affects the resilience of a network

June 22, 2018

Network theory is a method for analyzing the connections between nodes in a system. One of the most compelling aspects of network theory is that discoveries related to one field, such as cellular biology, can be abstracted ...

Water can be very dead, electrically speaking

June 21, 2018

In a study published in Science this week, the researchers describe the dielectric properties of water that is only a few molecules thick. Such water was previously predicted to exhibit a reduced electric response but it ...

0 comments

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.