Scientists rotate electron spin with electric field

Nov 01, 2007
Scientists rotate electron spin with electric field
An electron microscope photo of a nanostructure similar to that used in the experiment. The light-grey colors show the metal structure (made of gold) used to create an electric trap (white lines) for the electrons. A voltage (V) that changes with time is applied to the rightmost piece of metal. As a result, the electron, which is locked in the right trap, feels an electric field. This electric field causes the electron to move (white dotted line), so that the position of the electron changes with time. Credit: TU Delft

Researchers at the Delft University of Technology’s Kavli Institute of Nanoscience and the Foundation for Fundamental Research on Matter (FOM) have succeeded in controlling the spin of a single electron merely by using electric fields. This clears the way for a much simpler realization of the building blocks of a (future) super-fast quantum computer.

The scientists will publish their work in Science Express on Thursday 1 November.

Controlling the spin of a single electron is essential if this spin is to be used as the building block of a future quantum computer. An electron not only has a charge but, because of its spin, also behaves as a tiny magnet.

In a magnetic field, the spin can point in the same direction as the field or in the opposite direction, but the laws of quantum mechanics also allow the spin to exist in both states simultaneously. As a result, the spin of an electron is a very promising building block for the yet-to-be-developed quantum computer; a computer that, for certain applications, is far more powerful than a conventional computer.

At first glance it is surprising that the spin can be rotated by an electric field. However, we know from the Theory of Relativity that a moving electron can ‘feel’ an electric field as though it were a magnetic field. Researchers Katja Nowack and Dr. Frank Koppens therefore forced an electron to move through a rapidly-changing electric field. Working in collaboration with Prof. Yuli V. Nazarov, theoretical researcher at the Kavli Institute of Nanoscience Delft, they showed that it was indeed possible to turn the spin of the electron by doing so.

The advantage of controlling spin with electric fields rather than magnetic fields is that the former are easy to generate. It will also be easier to control various spins independently from one another - a requirement for building a quantum computer - using electric fields. The team, led by Dr. Lieven Vandersypen, is now going to apply this technique to a number of electrons.

Source: Delft University of Technology

Explore further: Galaxy dust findings confound view of early Universe

add to favorites email to friend print save as pdf

Related Stories

New pathway to valleytronics

Jan 27, 2015

A potential avenue to quantum computing currently generating quite the buzz in the high-tech industry is "valleytronics," in which information is coded based on the wavelike motion of electrons moving through ...

High-tech for huge, mobile ferris wheels

Jan 13, 2015

The world's largest transportable Ferris wheel is equipped with control and drive technology from Siemens. The 750-ton, 80-meter tall steel giant was built by the Munich-based company Maurer German Wheels ...

Recommended for you

Galaxy dust findings confound view of early Universe

Jan 31, 2015

What was the Universe like at the beginning of time? How did the Universe come to be the way it is today?—big questions and huge attention paid when scientists attempt answers. So was the early-universe ...

Seeking cracks in the Standard Model

Jan 30, 2015

In particle physics, it's our business to understand structure. I work on the Large Hadron Collider (LHC) and this machine lets us see and study the smallest structure of all; unimaginably tiny fundamental partic ...

Building the next generation of efficient computers

Jan 29, 2015

UConn researcher Bryan Huey has uncovered new information about the kinetic properties of multiferroic materials that could be a key breakthrough for scientists looking to create a new generation of low-energy, ...

User comments : 0

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.