Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

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 Magaña-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

Caught on camera -- chemical reactions 'filmed' at the single-molecule level March 22nd, 2017

Rare-earths become water-repellent only as they age March 22nd, 2017

Pulverizing e-waste is green, clean -- and cold: Rice, Indian Institute researchers use cryo-mill to turn circuit boards into separated powders March 21st, 2017

CRMGroup in Belgium uses a Deben three point bending stage in the development of new steel & coated steel products for automotive and other industrial applications March 21st, 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

Govt.-Legislation/Regulation/Funding/Policy

Electro-optical switch transmits data at record-low temperatures: Operating at temperatures near absolute zero, switch could enable significantly faster data processing with lower power consumption March 20th, 2017

AIM Photonics Welcomes Coventor as Newest Member: US-Backed Initiative Taps Process Modeling Specialist to Enable Manufacturing of High-Yield, High-Performance Integrated Photonic Designs March 16th, 2017

Researchers develop groundbreaking process for creating ultra-selective separation membranes: Discovery could greatly improve energy-efficiency of separation and purification processes in the chemical and petrochemical industries March 15th, 2017

Nanogate Expands Sustainability Management: Nanogate publishes a statement of compliance with the German Sustainability Code for the first time March 15th, 2017

Discoveries

Caught on camera -- chemical reactions 'filmed' at the single-molecule level March 22nd, 2017

Rare-earths become water-repellent only as they age March 22nd, 2017

Pulverizing e-waste is green, clean -- and cold: Rice, Indian Institute researchers use cryo-mill to turn circuit boards into separated powders March 21st, 2017

Electro-optical switch transmits data at record-low temperatures: Operating at temperatures near absolute zero, switch could enable significantly faster data processing with lower power consumption March 20th, 2017

Announcements

Caught on camera -- chemical reactions 'filmed' at the single-molecule level March 22nd, 2017

Rare-earths become water-repellent only as they age March 22nd, 2017

Pulverizing e-waste is green, clean -- and cold: Rice, Indian Institute researchers use cryo-mill to turn circuit boards into separated powders March 21st, 2017

CRMGroup in Belgium uses a Deben three point bending stage in the development of new steel & coated steel products for automotive and other industrial applications March 21st, 2017

Military

Graphene sheets capture cells efficiently: New method could enable pinpoint diagnostics on individual blood cells March 3rd, 2017

Bioinspired process makes materials light, robust, programmable at nano- to macro-scale: Ultralight web of silk nano fibers withstands load 4,000 times its weight February 28th, 2017

'Lossless' metamaterial could boost efficiency of lasers and other light-based devices February 20th, 2017

Engineers shrink microscope to dime-sized device February 17th, 2017

Research partnerships

Pulverizing e-waste is green, clean -- and cold: Rice, Indian Institute researchers use cryo-mill to turn circuit boards into separated powders March 21st, 2017

Nanoparticle paves the way for new triple negative breast cancer drug March 20th, 2017

Next-gen steel under the microscope March 18th, 2017

Block copolymer micellization as a protection strategy for DNA origami March 17th, 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