Clark School Home UMD

ECE News Story

Quantum Torque—Stronger Than Expected

Quantum Torque—Stronger Than Expected

Casimir Torque
Casimir Torque

A paper co-authored by Prof. Jeremy Munday (ECE/IREAP) and graduate student David Somers (Physics/IREAP) has been published in the November 3rd issue of Physical Review Letters (PRL). The paper is titled, “Casimir-Lifshitz Torque Enhancement by Retardation and Intervening Dielectrics.”

Quantum fluctuations of the vacuum give rise to minute forces and torques between microscale objects. While the force usually decreases when the objects are placed in a fluid, researchers in Prof. Munday’s group at the University of Maryland, College Park have now predicted that the torque (or rotation) caused by these fluctuations can increase in this situation, making it more accessible to current experimental techniques.

The Casimir effect is a remarkable phenomenon that results in a force between two objects as a result of quantum fluctuations. This force is a special class of electromagnetic interactions between large objects that result not from a net charge, but from the coordinated movement of electrons within the materials. They can cause not only a pushing or pulling force, but also a twisting torque that induces rotate into a particular orientation. This torque is so weak that it has eluded direct measurement, but Somers and Prof. Munday have now shown that a few common assumptions might have previously backfired for researchers - putting the effect within reach. For one, it is often assumed that the torque is strongest when the “dancing electrons” are allowed communicate instantly. In fact, this assumption results in a severe underestimation of the torque. Also, the torque can be enhanced by filling the gap between the objects with a fluid instead of air, which is also counter-intuitive.

These results show that the torque can be much stronger than often imagined. Hopefully, this will lead to a direct measurement and even rotational control in microscopic devices. Their research is supported by the National Science Foundation under Grant No. PHY-1506047.  

PRL is the world’s premier physics letter journal. It publishes short, high-quality reports of significant and notable results in the full arc of fundamental and interdisciplinary physics research.

Related Articles:
Spheres of attraction, brought together by quantum physics
Munday, Waks, and Collaborators’ Research Featured on Cover of Advanced Optical Materials
Jeremy Munday Receives 2017 Clark School Junior Faculty Outstanding Research Award
Electrically Controllable Optical Materials for Solar Sails Featured on Cover of Advanced Optical Materials 
“Solar Smart Window” Offers Privacy and Light Control on Demand
Clark School names Hamid Jafarkhani 2017 IHOF Inductee
Q&A with ECE's New Faculty, Kevin M. Daniels and Yasser Shoukry
Munday, Ha, and Collaborators' Research featured on the Cover of ACS Applied Materials and Interfaces
UMD Physicists Discover “Smoke Rings” Made of Laser Light
Former Chair of ECE and VP for Research, Dr. Patrick G. O'Shea, Named President of the University of College Cork in Ireland (UCC)

November 6, 2017

Prev   Next

Current Headlines

Munday, Waks, and Collaborators’ Research Featured on Cover of Advanced Optical Materials

ECE Names 2017-2018 Distinguished Dissertation Fellows

Hacking Tomorrow's Tech World

UMD Celebrates Invention of Year Winners, Ventures, and Partnerships at 'Innovate Maryland'

Ulukus named Anthony Ephremides Professor in Information Sciences and Systems

Four Clark School Professors Receive Competitive DURIP Grants

Dinesh Manocha Elected AAAI Fellow

Maryland researchers develop computational approach to understanding brain dynamics

News Resources

Return to Newsroom

Search News

Archived News

Events Resources

Events Calendar

Additional Resources

UM Newsdesk

Faculty Experts