Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Which qubit my dear? New method to distinguish between neighbouring quantum bits

This is Professor Michelle Simmons, director of the Australian Centre of Excellence for Quantum Computation and Communication Technology.

Credit: UNSW
This is Professor Michelle Simmons, director of the Australian Centre of Excellence for Quantum Computation and Communication Technology.

Credit: UNSW

Abstract:
Researchers at the University of New South Wales have proposed a new way to distinguish between quantum bits that are placed only a few nanometres apart in a silicon chip, taking them a step closer to the construction of a large-scale quantum computer.

Which qubit my dear? New method to distinguish between neighbouring quantum bits

Sydney, Australia | Posted on June 18th, 2013

Quantum bits, or qubits, are the basic building blocks of quantum computers - ultra-powerful devices that will offer enormous advantages for solving complex problems.

Professor Michelle Simmons, leader of the research team, said a qubit based on the spin of an individual electron bound to a phosphorus atom within a silicon chip is one of the most promising systems for building a practical quantum computer, due to silicon's widespread use in the microelectronics industry.

"However, to be able to couple electron-spins on single atom qubits, the qubits need to be placed with atomic precision, within just a few tens of nanometres of each other," she says.

"This poses a technical problem in how to make them, and an operational problem in how to control them independently when they are so close together."

The UNSW team, in collaboration with theorists at Sandia National Laboratories in New Mexico, has found a solution to both these problems. Their study is published in the journal Nature Communications.

In a significant feat of atomic engineering, they were able to read-out the spins of individual electrons on a cluster of phosphorus atoms that had been placed precisely in silicon. They also propose a new method for distinguishing between neighbouring qubits that are only a few nanometres apart.

"It is a daunting challenge to rotate the spin of each qubit individually," says Holger Büch, lead author of the new study.




"If each electron spin-qubit is hosted by a single phosphorus atom, every time you try to rotate one qubit, all the neighbouring qubits will rotate at the same time - and quantum computation will not work. "

"But if each electron is hosted by a different number of phosphorus atoms, then the qubits will respond to different electromagnetic fields - and each qubit can be distinguished from the others around it," he says.

The UNSW team is part of the Australian Centre of Excellence for Quantum Computation and Communication Technology, a world-leading research centre headquartered in Sydney, Australia.

"This is an elegant and satisfying piece of work," says Professor Simmons, centre director and Mr Büch's PhD supervisor. "This first demonstration that we can maintain long spin lifetimes of electrons on multi-donor systems is very powerful. It offers a new method for addressing individual qubits, putting us one step closer to realising a practical, large-scale quantum computer."

To make the tiny device, the researchers deposited a layer of hydrogen on a silicon wafer and used a scanning tunnelling microscope to create a pattern on the surface in an ultra-high vacuum.

This was then exposed to phosphine gas and annealed at 350 degrees so phosphorus atoms became incorporated precisely into the silicon. The device was then buried in another layer of silicon.

In a quantum computer information is stored in the spin, or magnetic orientation, of an electron. This spin can not only be in two states - up and down - just as in a classical computer.

It can also be in a combination of both states at the same time, allowing exponentially larger amounts of information to be stored and processed in parallel.

####

For more information, please click here

Contacts:
Professor Michelle Simmons:

+ 61 (2) 9385 6313

UNSW Science media:
Deborah Smith

61-293-857-307

Copyright © University of New South Wales

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

Imaging

JEOL Introduces New Best-in-Class Field Emission SEM September 2nd, 2015

News and information

Atomic Force Microscopes from Asylum Research Guide the Development of Thin Film Deposition and Etch Processes September 2nd, 2015

For 2-D boron, it's all about that base: Rice University theorists show flat boron form would depend on metal substrates September 2nd, 2015

Silk bio-ink could help advance tissue engineering with 3-D printers September 2nd, 2015

Phagraphene, a 'relative' of graphene, discovered September 2nd, 2015

Physics

Hot electrons point the way to perfect light absorption: Physicists study how to achieve perfect absorption of light with the help of rough ultrathin films September 1st, 2015

Scientists 'squeeze' light one particle at a time: A team of scientists have measured a bizarre effect in quantum physics, in which individual particles of light are said to have been 'squeezed' -- an achievement which at least one textbook had written off as hopeless September 1st, 2015

Using ultrathin sheets to discover new class of wrapped shapes: UMass Amherst materials researchers describe a new regime of wrapped shapes August 31st, 2015

Seeing quantum motion August 30th, 2015

Spintronics

Spintronics: Molecules stabilizing magnetism: Organic molecules fixing the magnetic orientation of a cobalt surface/ building block for a compact and low-cost storage technology/ publication in Nature Materials July 25th, 2015

Penn researchers discover new chiral property of silicon, with photonic applications July 25th, 2015

Spintronics just got faster July 20th, 2015

Fundamental observation of spin-controlled electrical conduction in metals: Ultrafast terahertz spectroscopy yields direct insight into the building block of modern magnetic memories July 6th, 2015

Chip Technology

For 2-D boron, it's all about that base: Rice University theorists show flat boron form would depend on metal substrates September 2nd, 2015

Phagraphene, a 'relative' of graphene, discovered September 2nd, 2015

Nanometrics to Participate in the Citi 2015 Global Technology Conference August 26th, 2015

Kwansei Gakuin University in Hyogo, Japan, uses Raman microscopy to study crystallographic defects in silicon carbide wafers August 25th, 2015

Quantum Computing

A little light interaction leaves quantum physicists beaming August 25th, 2015

Surprising discoveries about 2-D molybdenum disulfide: Berkeley Lab researchers use award-winning campanile probe on promising semiconductor August 15th, 2015

New optical chip lights up the race for quantum computer August 14th, 2015

Quantum computing advance locates neutral atoms August 12th, 2015

Discoveries

For 2-D boron, it's all about that base: Rice University theorists show flat boron form would depend on metal substrates September 2nd, 2015

Silk bio-ink could help advance tissue engineering with 3-D printers September 2nd, 2015

Phagraphene, a 'relative' of graphene, discovered September 2nd, 2015

A marine creature's magic trick explained: Crystal structures on the sea sapphire's back appear differently depending on the angle of reflection September 2nd, 2015

Announcements

For 2-D boron, it's all about that base: Rice University theorists show flat boron form would depend on metal substrates September 2nd, 2015

Silk bio-ink could help advance tissue engineering with 3-D printers September 2nd, 2015

Phagraphene, a 'relative' of graphene, discovered September 2nd, 2015

A marine creature's magic trick explained: Crystal structures on the sea sapphire's back appear differently depending on the angle of reflection September 2nd, 2015

Tools

Oxford Instruments’ Triton Cryofree dilution refrigerator selected by Oxford University for developing scalable quantum nanodevices September 2nd, 2015

JEOL Introduces New Best-in-Class Field Emission SEM September 2nd, 2015

Atomic Force Microscopes from Asylum Research Guide the Development of Thin Film Deposition and Etch Processes September 2nd, 2015

Nanolab Technologies LEAPS Forward with High-Performance Analysis Services to the World: Nanolab Orders Advanced Local Electrode Atom Probe (LEAP®) Microscope from CAMECA Unit of AMETEK Materials Analysis Division August 27th, 2015

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







Car Brands
Buy website traffic