New knowledge about 'flawed' diamonds could speed the development of diamond-based quantum computers

Oct 11, 2011
Calculated energy surface of the 3E excited state of a diamond nitrogen-vacancy center as a function of distortions, a shape that is often referred to as a "warped Mexican hat." Credit: University at buffalo

A University at Buffalo-led research team has established the presence of a dynamic Jahn-Teller effect in defective diamonds, a finding that will help advance the development of diamond-based systems in applications such as quantum information processing.

"We normally want things to be perfect, but defects are actually very important in terms of ," said Peihong Zhang, the UB associate professor of physics who led the study. "There are many proposals for the application of defective diamonds, ranging from quantum computing to , and our research is one step toward a better understanding of these defect systems."

The research was published online Sept. 30 in (PDF).

The findings deal with diamonds whose crystal structure contains a particular defect: a that sits alongside a vacant space in an otherwise perfect lattice made only of carbon.

At the point of the imperfection -- the so-called "nitrogen-vacancy center" -- a single electron can jump between different energy states. (The electron rises to a higher, "excited" energy state when it absorbs a photon and falls back to a lower energy state when it emits a photon).

Understanding how the diamond system behaves when the electron rises to an called a "3E" state is critical to the success of such proposed applications as quantum computing.

The problem is that at the nitrogen-vacancy center, the 3E state has two orbital components with exactly the same energy -- a configuration that is inherently unstable.

In response, the lattice "stabilizes" by rearranging itself. Atoms near the nitrogen-vacancy center move slightly, resulting in a new geometry that has a lower energy and is more stable.

This morphing is known as the Jahn-Teller effect, and until recently, the effect's precise parameters in defective diamonds remained unknown.

Zhang and colleagues from the Rensselaer Polytechnic Institute in Troy, N.Y., are the first to crack that mystery. Using UB's supercomputing facility, the Center for Computational Research, the team conducted calculations that reveal how, exactly, the diamond lattice distorts.

Their findings align with experimental results from other research studies, and shed light on important topics such as how long an excited electron at the nitrogen-vacancy center will stay coherently at a higher .

Explore further: New research signals big future for quantum radar

Related Stories

Dark spins light up

Oct 25, 2005

Want to see a diamond? Forget the jewellery store - try a physics laboratory. In the November issue of Nature Physics, Ryan Epstein and colleagues demonstrate the power of their microscope for imaging individual nitrogen ...

The diamond’s quantum memory

Aug 10, 2011

For years, quantum computers have been the holy grail of quantum technology. When a normal computer has to solve a number of problems, it can only execute them one after the other. In contrast, a quantum computer ...

Diamonds and the holy grail of quantum computing

Jun 29, 2010

Since Richard Feynman's first envisioned the quantum computer in 1982, there have been many studies of potential candidates -- computers that use quantum bits, or qubits, capable of holding an more than one value at a time ...

Recommended for you

New filter could advance terahertz data transmission

Feb 27, 2015

University of Utah engineers have discovered a new approach for designing filters capable of separating different frequencies in the terahertz spectrum, the next generation of communications bandwidth that ...

The super-resolution revolution

Feb 27, 2015

Cambridge scientists are part of a resolution revolution. Building powerful instruments that shatter the physical limits of optical microscopy, they are beginning to watch molecular processes as they happen, ...

Precision gas sensor could fit on a chip

Feb 27, 2015

Using their expertise in silicon optics, Cornell engineers have miniaturized a light source in the elusive mid-infrared (mid-IR) spectrum, effectively squeezing the capabilities of a large, tabletop laser onto a 1-millimeter ...

A new X-ray microscope for nanoscale imaging

Feb 27, 2015

Delivering the capability to image nanostructures and chemical reactions down to nanometer resolution requires a new class of x-ray microscope that can perform precision microscopy experiments using ultra-bright ...

New research signals big future for quantum radar

Feb 26, 2015

A prototype quantum radar that has the potential to detect objects which are invisible to conventional systems has been developed by an international research team led by a quantum information scientist at the University ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

KBK
1 / 5 (1) Nov 11, 2011
Now..connect this basic configuration understanding to browns gas.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.