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: Heat makes electrons spin in magnetic superconductors

Related Stories

Heat makes electrons spin in magnetic superconductors

8 hours ago

Physicists have shown how heat can be exploited for controlling magnetic properties of matter. The finding helps in the development of more efficient mass memories. The result was published yesterday in Physical Review Le ...

Ultra-sensitive sensor detects individual electrons

Apr 23, 2015

A Spanish-led team of European researchers at the University of Cambridge has created an electronic device so accurate that it can detect the charge of a single electron in less than one microsecond. It has ...

Putting a new spin on computing memory

Apr 22, 2015

Ever since computers have been small enough to be fixtures on desks and laps, their central processing has functioned something like an atomic Etch A Sketch, with electromagnetic fields pushing data bits ...

Electron trapping harnessed to make light sensors

Apr 21, 2015

Traps. Whether you're squaring off against the Empire or trying to wring electricity out of sunlight, they're almost never a good thing. But sometimes you can turn that trap to your advantage. A team from ...

Quantum Criticality in life's proteins (Update)

Apr 15, 2015

(Phys.org)—Stuart Kauffman, from the University of Calgary, and several of his colleagues have recently published a paper on the Arxiv server titled 'Quantum Criticality at the Origins of Life'. The id ...

Recommended for you

Heat makes electrons spin in magnetic superconductors

Apr 24, 2015

Physicists have shown how heat can be exploited for controlling magnetic properties of matter. The finding helps in the development of more efficient mass memories. The result was published yesterday in Physical Review Le ...

ICARUS neutrino experiment to move to Fermilab

Apr 23, 2015

A group of scientists led by Nobel laureate Carlo Rubbia will transport the world's largest liquid-argon neutrino detector across the Atlantic Ocean from CERN to its new home at the US Department of Energy's ...

National security on the move with high energy physics

Apr 23, 2015

Scientists are developing a portable technology that will safely and quickly detect nuclear material hidden within large objects such as shipping cargo containers or sealed waste drums. The researchers, led ...

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.