Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Tricking the Uncertainty Principle: Researchers at Caltech find a way to sidestep the quantum "noise" that limits the precision of ultrasensitive position measurements

The tiny aluminum device—only 40 microns long and 100 nanometers thick—in which Caltech researchers observed the quantum noise from microwaves.
Credit: Chan Lei and Keith Schwab/Caltech
The tiny aluminum device—only 40 microns long and 100 nanometers thick—in which Caltech researchers observed the quantum noise from microwaves.

Credit: Chan Lei and Keith Schwab/Caltech

Abstract:
Caltech researchers have found a way to make measurements that go beyond the limits imposed by quantum physics.

Tricking the Uncertainty Principle: Researchers at Caltech find a way to sidestep the quantum "noise" that limits the precision of ultrasensitive position measurements

Pasadena, CA | Posted on May 15th, 2014

Today, we are capable of measuring the position of an object with unprecedented accuracy, but quantum physics and the Heisenberg uncertainty principle place fundamental limits on our ability to measure. Noise that arises as a result of the quantum nature of the fields used to make those measurements imposes what is called the "standard quantum limit." This same limit influences both the ultrasensitive measurements in nanoscale devices and the kilometer-scale gravitational wave detector at LIGO. Because of this troublesome background noise, we can never know an object's exact location, but a recent study provides a solution for rerouting some of that noise away from the measurement.

The findings were published online in the May 15 issue of Science Express.

"If you want to know where something is, you have to scatter something off of it," explains Professor of Applied Physics Keith Schwab, who led the study. "For example, if you shine light at an object, the photons that scatter off provide information about the object. But the photons don't all hit and scatter at the same time, and the random pattern of scattering creates quantum fluctuations"—that is, noise. "If you shine more light, you have increased sensitivity, but you also have more noise. Here we were looking for a way to beat the uncertainty principle—to increase sensitivity but not noise."

Schwab and his colleagues began by developing a way to actually detect the noise produced during the scattering of microwaves—electromagnetic radiation that has a wavelength longer than that of visible light. To do this, they delivered microwaves of a specific frequency to a superconducting electronic circuit, or resonator, that vibrates at 5 gigahertz—or 5 billion times per second. The electronic circuit was then coupled to a mechanical device formed of two metal plates that vibrate at around 4 megahertz—or 4 million times per second. The researchers observed that the quantum noise of the microwave field, due to the impact of individual photons, made the mechanical device shake randomly with an amplitude of 10-15 meters, about the diameter of a proton.

"Our mechanical device is a tiny square of aluminum—only 40 microns long, or about the diameter of a hair. We think of quantum mechanics as a good description for the behaviors of atoms and electrons and protons and all of that, but normally you don't think of these sorts of quantum effects manifesting themselves on somewhat macroscopic objects," Schwab says. "This is a physical manifestation of the uncertainty principle, seen in single photons impacting a somewhat macroscopic thing."

Once the researchers had a reliable mechanism for detecting the forces generated by the quantum fluctuations of microwaves on a macroscopic object, they could modify their electronic resonator, mechanical device, and mathematical approach to exclude the noise of the position and motion of the vibrating metal plates from their measurement.

The experiment shows that a) the noise is present and can be picked up by a detector, and b) it can be pushed to someplace that won't affect the measurement. "It's a way of tricking the uncertainty principle so that you can dial up the sensitivity of a detector without increasing the noise," Schwab says.

Although this experiment is mostly a fundamental exploration of the quantum nature of microwaves in mechanical devices, Schwab says that this line of research could one day lead to the observation of quantum mechanical effects in much larger mechanical structures. And that, he notes, could allow the demonstration of strange quantum mechanical properties like superposition and entanglement in large objects—for example, allowing a macroscopic object to exist in two places at once.

"Subatomic particles act in quantum ways—they have a wave-like nature—and so can atoms, and so can whole molecules since they're collections of atoms," Schwab says. "So the question then is: Can you make bigger and bigger objects behave in these weird wave-like ways? Why not? Right now we're just trying to figure out where the boundary of quantum physics is, but you never know."

This work was published in an article titled "Mechanically Detecting and Avoiding the Quantum Fluctuations of a Microwave Field." Other Caltech coauthors include senior researcher Junho Suh; graduate students Aaron J. Weinstein, Chan U. Lei, and Emma E. Wollman; and Steven K. Steinke, visitor in applied physics and materials science. The work was funded by the Institute for Quantum Information and Matter, the Defense Advanced Research Projects Agency, and the National Science Foundation. The device was fabricated in Caltech's Kavli Nanoscience Institute, of which Schwab is a codirector.

Written by Jessica Stoller-Conrad

####

For more information, please click here

Contacts:
Brian Bell
(626) 395-5832

Copyright © California Institute of Technology

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Sandia use confined nanoparticles to improve hydrogen storage materials performance: Big changes from a small package for hydrogen storage February 25th, 2017

New nano approach could cut dose of leading HIV treatment in half February 24th, 2017

Atom-scale oxidation mechanism of nanoparticles helps develop anti-corrosion materials February 24th, 2017

Atomic force imaging used to study nematodes: KFU bionanotechnology lab (head - Dr. Rawil Fakhrullin) has obtained 3-D images of nematodes' cuticles February 23rd, 2017

Physics

Breakthrough with a chain of gold atoms: In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport February 20th, 2017

Research reveals novel quantum state in strange insulating materials February 14th, 2017

Sorting machine for atoms:Researchers at the University of Bonn clear a further hurdle on the path to creating quantum computers February 10th, 2017

The shape of melting in two dimensions: University of Michigan team uses Titan to explore fundamental phase transitions February 2nd, 2017

Discoveries

Sandia use confined nanoparticles to improve hydrogen storage materials performance: Big changes from a small package for hydrogen storage February 25th, 2017

New nano approach could cut dose of leading HIV treatment in half February 24th, 2017

Atom-scale oxidation mechanism of nanoparticles helps develop anti-corrosion materials February 24th, 2017

Atomic force imaging used to study nematodes: KFU bionanotechnology lab (head - Dr. Rawil Fakhrullin) has obtained 3-D images of nematodes' cuticles February 23rd, 2017

Announcements

Sandia use confined nanoparticles to improve hydrogen storage materials performance: Big changes from a small package for hydrogen storage February 25th, 2017

New nano approach could cut dose of leading HIV treatment in half February 24th, 2017

Atom-scale oxidation mechanism of nanoparticles helps develop anti-corrosion materials February 24th, 2017

Atomic force imaging used to study nematodes: KFU bionanotechnology lab (head - Dr. Rawil Fakhrullin) has obtained 3-D images of nematodes' cuticles February 23rd, 2017

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers

Sandia use confined nanoparticles to improve hydrogen storage materials performance: Big changes from a small package for hydrogen storage February 25th, 2017

New nano approach could cut dose of leading HIV treatment in half February 24th, 2017

Atom-scale oxidation mechanism of nanoparticles helps develop anti-corrosion materials February 24th, 2017

Molecular phenomenon discovered by advanced NMR facility: Cutting edge technology has shown a molecule self-assembling into different forms when passing between solution state to solid state, and back again - a curious phenomenon in science - says research by the University of Wa February 22nd, 2017

Tools

Atomic force imaging used to study nematodes: KFU bionanotechnology lab (head - Dr. Rawil Fakhrullin) has obtained 3-D images of nematodes' cuticles February 23rd, 2017

JPK selects compact tensile stage from Deben for their NanoWizard® AFM platform to broaden capabilities for materials characterisation February 22nd, 2017

Molecular phenomenon discovered by advanced NMR facility: Cutting edge technology has shown a molecule self-assembling into different forms when passing between solution state to solid state, and back again - a curious phenomenon in science - says research by the University of Wa February 22nd, 2017

Strem Chemicals and Dotz Nano Ltd. Sign Distribution Agreement for Graphene Quantum Dots Collaboration February 21st, 2017

Quantum nanoscience

The speed limit for intra-chip communications in microprocessors of the future January 23rd, 2017

First experimental proof of a 70 year old physics theory: First observation of magnetic phase transition in 2-D materials, as predicted by the Nobel winner Onsager in 1943 January 6th, 2017

Quantum simulation technique yields topological soliton state in SSH model January 3rd, 2017

Diamonds are technologists' best friends: Researchers from the Lomonosov Moscow State University have grown needle- and thread-like diamonds and studied their useful properties December 30th, 2016

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project