Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > New technique uses fraction of measurements to efficiently find quantum wave functions

Abstract:
The result of every possible measurement on a quantum system is coded in its wave function, which until recently could be found only by taking many different measurements of a system and estimating a wave function that best fit all those measurements. Just two years ago, with the advent of a technique called direct measurement, scientists discovered they could reliably determine a system's wave function by "weakly" measuring one of its variables (e.g. position) and "strongly" measuring a complementary variable (momentum). Researchers at the University of Rochester have now taken this method one step forward by combining direct measurement with an efficient computational technique.

New technique uses fraction of measurements to efficiently find quantum wave functions

Rochester, NY | Posted on August 28th, 2014

The new method, called compressive direct measurement, allowed the team to reconstruct a quantum state at 90 percent fidelity (a measure of accuracy) using only a quarter of the measurements required by previous methods.

"We have, for the first time, combined weak measurement and compressive sensing to demonstrate a revolutionary, fast method for measuring a high-dimensional quantum state," said Mohammad Mirhosseini, a graduate student in the Quantum Photonics research group at the University of Rochester and lead author of a paper appearing today in Physical Review Letters.

The research team, which also included graduate students Omar Magańa-Loaiza and Seyed Mohammad Hashemi Rafsanjani, and Professor Robert Boyd, initially tested their method on a 192-dimensional state. Finding success with that large state, they then took on a massive, 19,200-dimensional state. Their efficient technique sped up the process 350-fold and took just 20 percent of the total measurements required by traditional direct measurement to reconstruct the state.

"To reproduce our result using a direct measurement alone would require more than one year of exposure time," said Rafsanjani. "We did the experiment in less than 48 hours."

While recent compressive sensing techniques have been used to measure sets of complementary variables like position and momentum, Mirhosseini explains that their method allows them to measure the full wave function.

Compression is widely used in the classical world of digital media, including recorded music, video, and pictures. The MP3s on your phone, for example, are audio files that have had bits of information squeezed out to make the file smaller at the cost of losing a small amount of audio quality along the way.

In digital cameras, the more pixels you can gather from a scene, the higher the image quality and the larger the file will be. But it turns out that most of those pixels don't convey essential information that needs to be captured from the scene. Most of them can be reconstructed later. Compressive sensing works by randomly sampling portions from all over the scene, and using those patterns to fill in the missing information.

Similarly for quantum states, it is not necessary to measure every single dimension of a multidimensional state. It takes only a handful of measurements to get a high-quality image of a quantum system.

The method introduced by Mirhosseini et al. has important potential applications in the field of quantum information science. This research field strives to make use of fundamental quantum effects for diverse applications, including secure communication, teleportation of quantum states, and ideally to perform quantum computation. This latter process holds great promise as a method that can, in principle, lead to a drastic speed-up of certain types of computation. All of these applications require the use of complicated quantum states, and the new method described here offers an efficient means to characterize these states.

###

Research funding was provided by the Defense Advanced Research Projects Agency's (DARPA) Information in a Photon (InPho) program, U.S. Defense Threat Reduction Agency (DTRA), National Science Foundation (NSF), El Consejo Nacional de Ciencia y Tecnología (CONACYT) and Canadian Excellence Research Chair (CERC).

####

For more information, please click here

Contacts:
Peter Iglinski

585-273-4726

Copyright © University of Rochester

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

First Observation of Electronic Structure in Ag-Rh Alloy Nanoparticles Having Hydrogen Absorbing: Storage Property –Attempting to solve the mystery of why Ag-Rh alloy nanoparticles have a similar property to Pd– October 30th, 2014

Iranians Present Model to Predict Photocatalytic Process in Removal of Pollutants October 30th, 2014

Production of Biocompatible Polymers in Iran October 30th, 2014

Amorphous Coordination Polymer Particles as alternative to classical nanoplatforms for nanomedicine October 30th, 2014

Physics

Sussex physicists find simple solution for quantum technology challenge October 28th, 2014

New evidence for an exotic, predicted superconducting state October 27th, 2014

Solid nanoparticles can deform like a liquid: Unexpected finding shows tiny particles keep their internal crystal structure while flexing like droplets October 12th, 2014

Unconventional photoconduction in an atomically thin semiconductor: New mechanism of photoconduction could lead to next-generation excitonic devices October 9th, 2014

Govt.-Legislation/Regulation/Funding/Policy

'Electronic skin' could improve early breast cancer detection October 29th, 2014

New solar power material converts 90 percent of captured light into heat: SunShot Project aims to make solar cost competitive October 29th, 2014

Tiny carbon nanotube pores make big impact October 29th, 2014

Microrockets fueled by water neutralize chemical and biological warfare agents October 29th, 2014

Discoveries

First Observation of Electronic Structure in Ag-Rh Alloy Nanoparticles Having Hydrogen Absorbing: Storage Property –Attempting to solve the mystery of why Ag-Rh alloy nanoparticles have a similar property to Pd– October 30th, 2014

Iranians Present Model to Predict Photocatalytic Process in Removal of Pollutants October 30th, 2014

Production of Biocompatible Polymers in Iran October 30th, 2014

Amorphous Coordination Polymer Particles as alternative to classical nanoplatforms for nanomedicine October 30th, 2014

Announcements

First Observation of Electronic Structure in Ag-Rh Alloy Nanoparticles Having Hydrogen Absorbing: Storage Property –Attempting to solve the mystery of why Ag-Rh alloy nanoparticles have a similar property to Pd– October 30th, 2014

Iranians Present Model to Predict Photocatalytic Process in Removal of Pollutants October 30th, 2014

Production of Biocompatible Polymers in Iran October 30th, 2014

Amorphous Coordination Polymer Particles as alternative to classical nanoplatforms for nanomedicine October 30th, 2014

Military

Microrockets fueled by water neutralize chemical and biological warfare agents October 29th, 2014

Breakthrough in molecular electronics paves the way for DNA-based computer circuits in the future: DNA-based programmable circuits could be more sophisticated, cheaper and simpler to make October 27th, 2014

NanoTechnology for Defense (NT4D) October 22nd, 2014

Imaging electric charge propagating along microbial nanowires October 20th, 2014

Research partnerships

First Observation of Electronic Structure in Ag-Rh Alloy Nanoparticles Having Hydrogen Absorbing: Storage Property –Attempting to solve the mystery of why Ag-Rh alloy nanoparticles have a similar property to Pd– October 30th, 2014

Sussex physicists find simple solution for quantum technology challenge October 28th, 2014

Molecular beacons shine light on how cells 'crawl' October 27th, 2014

New evidence for an exotic, predicted superconducting state October 27th, 2014

Quantum nanoscience

NIST quantum probe enhances electric field measurements October 8th, 2014

Quantum environmentalism: Putting a qubit's surroundings to good use October 2nd, 2014

Rice launches Center for Quantum Materials: RCQM will immerse global visitors in cross-disciplinary research September 30th, 2014

Big Results Require Big Ambitions: Three young UCSB faculty receive CAREER awards from the National Science Foundation September 18th, 2014

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







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE