Researchers Suggest Quantum Dots as Media for Teleportation

Jun 21, 2007 Laura Mgrdichian feature

According to recent research, tiny clusters of atoms known as quantum dots may be excellent media for quantum teleportation, a physics phenomenon in which information – in the form of a quantum state, a very specific mathematical “signature” of an atom – can be transmitted almost instantaneously to a distant location without having to physically travel through space. Teleportation is one facet of quantum information science, a developing field that could have a major impact on computing and communications.

Here, researchers focus on semiconductor quantum dots containing as few as a thousand atoms of a semiconducting element, such as silicon, and having diameters as small as one nanometer. They are often referred to as “artificial atoms” because their behavior can be quite similar to a single atom.

For example, a semiconductor quantum dot's electrons can be confined in a way similar to how a single atom's electrons are bound. Therefore, a quantum dot can be described by a single quantum state, despite consisting of hundreds or thousands of atoms.

Researchers Leong Chuan Kwek and K.W. Choo of Nanyang Technological University in Singapore modeled a teleportation system consisting of two quantum dots. They first investigated how the fidelity of the teleportation process would be affected by quantum “entanglement” – when two or more quantum states have to be described with reference to each other, even when spatially separated.

The model revealed that the entanglement of the dots is proportional to the fidelity: as one increases, the other increases. Kwek and Choo then developed general equations that would yield a suitable magnetic field, dot-to-dot distance, and temperature (which would all depend on the size of the dots and other variables) such that the fidelity of the system would be better than the average fidelity of non-quantum communications.

“Our work provides some preliminary estimates on the way self-assembled quantum dots might be fabricated in terms of inter-dot distances for experiments at room temperature,” Kwek told PhysOrg.com.

He and Choo also studied how the system would handle “decoherence,” the often unavoidable interaction of a quantum system with its environment, which compromises the transfer process. Decoherence is one major issue facing quantum computing. Two decoherence models show, however, that the quantum-dot system could still function under a moderate amount of decoherence.

Finally, the researchers used the model to study a quantum-state transfer or swapping of states between two quantum dots, an ability necessary for quantum information processing. They determined that a “perfect” transfer is possible using a quantum-dot teleportation system, meaning that the transferred quantum state is exactly the same as the initial quantum state of the first dot.

Citation: K.W. Choo and L. C. Kwek, “Quantum dot as a resource for teleportation and state swapping.” Phys. Rev. B 75 205321 (2007)

Copyright 2007 PhysOrg.com.
All rights reserved. This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of PhysOrg.com.

Explore further: Using strong lasers, investigators observe frenzy of electrons in a new material

add to favorites email to friend print save as pdf

Related Stories

A new ultrabright source of entangled photon pairs

Jul 09, 2010

At the very heart of applications such as quantum cryptography, computation and teleportation lies a fascinating phenomenon known as "entanglement". Two photons are entangled if the properties of one depend ...

Recommended for you

Shiny quantum dots brighten future of solar cells

Apr 14, 2014

(Phys.org) —A house window that doubles as a solar panel could be on the horizon, thanks to recent quantum-dot work by Los Alamos National Laboratory researchers in collaboration with scientists from University ...

User comments : 0

More news stories

Shiny quantum dots brighten future of solar cells

(Phys.org) —A house window that doubles as a solar panel could be on the horizon, thanks to recent quantum-dot work by Los Alamos National Laboratory researchers in collaboration with scientists from University ...

Polymer microparticles could help verify goods

Some 2 to 5 percent of all international trade involves counterfeit goods, according to a 2013 United Nations report. These illicit products—which include electronics, automotive and aircraft parts, pharmaceuticals, ...

Low Vitamin D may not be a culprit in menopause symptoms

A new study from the Women's Health Initiative (WHI) shows no significant connection between vitamin D levels and menopause symptoms. The study was published online today in Menopause, the journal of The North American Menopa ...

Astronomers: 'Tilt-a-worlds' could harbor life

A fluctuating tilt in a planet's orbit does not preclude the possibility of life, according to new research by astronomers at the University of Washington, Utah's Weber State University and NASA. In fact, ...