Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Working towards an optical integrated circuit

An artist's view of a photonic circuit with molecular building blocks. A single-molecule optical transistor is depitcted using a standard symbol for an electronic transistor. (Image: Robert Lettow)
An artist's view of a photonic circuit with molecular building blocks. A single-molecule optical transistor is depitcted using a standard symbol for an electronic transistor. (Image: Robert Lettow)

Abstract:
ETH Zurich researchers have successfully created an optical transistor from a single molecule. This has brought them one step closer to an optical computer.

Working towards an optical integrated circuit

Zurich | Posted on July 8th, 2009

Internet connections and computers need to be ever faster and more powerful nowadays. However, conventional central processing units (CPUs) limit the performance of computers, for example because they produce an enormous amount of heat. The millions of transistors that switch and amplify the electronic signals in the CPUs are responsible for this. One square centimeter of CPU can emit up to 125 watts of heat, which is more than ten times as much as a square centimeter of an electric hotplate.

Photons instead of electrons

This is why scientists have been trying for some time to find ways to produce integrated circuits that operate on the basis of photons instead of electrons. The reason is that photons do not only generate much less heat than electrons, but they also enable considerably higher data transfer rates.

Although a large part of telecommunications engineering nowadays is based on optical signal transmission, the necessary encoding of the information is generated using electronically controlled switches. A compact optical transistor is still a long way off. Vahid Sandoghdar, Professor at the Laboratory of Physical Chemistry of ETH Zurich, explains that, "Comparing the current state of this technology with that of electronics, we are somewhat closer to the vacuum tube amplifiers that were around in the fifties than we are to today's integrated circuits."

However, his research group has now achieved a decisive breakthrough by successfully creating an optical transistor with a single molecule. For this, they have made use of the fact that a molecule's energy is quantized: when laser light strikes a molecule that is in its ground state, the light is absorbed. As a result, the laser beam is quenched. Conversely, it is possible to release the absorbed energy again in a targeted way with a second light beam. This occurs because the beam changes the molecule's quantum state, with the result that the light beam is amplified. This so-called stimulated emission, which Albert Einstein described over 90 years ago, also forms the basis for the principle of the laser.

Focusing on a nano scale

Jaesuk Hwang, first author of the study and a scientific member of Sandoghdar's nano-optics group, explains that, "Amplification in a conventional laser is achieved by an enormous number of molecules." By focusing a laser beam on only a single tiny molecule, the ETH Zurich scientists have now been able to generate stimulated emission using just one molecule. They were helped in this by the fact that, at low temperatures, molecules seem to increase their apparent surface area for interaction with light. The researchers therefore needed to cool the molecule down to minus 272 degrees Celsius (minus 457.6 degrees Fahrenheit), i.e. one degree above absolute zero. In this case, the enlarged surface area corresponded approximately to the diameter of the focused laser beam.

Switching light with light

By using one laser beam to prepare the quantum state of a single molecule in a controlled fashion, scientists could significantly attenuate or amplify a second laser beam. This mode of operation is identical to that of a conventional transistor, in which electrical potential can be used to modulate a second signal.

Innovative computer still a long way off

Thus component parts such as the new single molecule transistor may also pave the way for a quantum computer. Sandoghdar says, "Many more years of research will still be needed before photons replace electrons in transistors. In the meantime, scientists will learn to manipulate and control quantum systems in a targeted way, moving them closer to the dream of a quantum computer."

Reference:
J. Hwang, M. Pototschnig, R. Lettow, G. Zumofen, A. Renn, S. Götzinger, V. Sandoghda: A single-molecule opzical transistor, Nature (2009) 460, 76-80,doi:10.1038/nature08134

####

About ETH Zurich
ETH Zurich (German: Eidgenössische Technische Hochschule Zürich) or Swiss Federal Institute of Technology Zurich is a science and technology university in the City of Zurich, Switzerland. Locals sometimes refer to it by the name Poly, derived from the original name Eidgenössisches Polytechnikum or Federal Polytechnic Institute.

From Wikipedia, the free encyclopedia

For more information, please click here

Contacts:
ETH Zurich
Editorial Office
HG F 41
Raemistrasse 101
8092 Zurich
SWITZERLAND

Fax +41 44 632 17 16

Copyright © ETH Zurich

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

News and information

Spin current detection in quantum materials unlocks potential for alternative electronics October 15th, 2017

Quantum manipulation power for quantum information processing gets a boost: Improving the efficiency of quantum heat engines involves reducing the number of photons in a cavity, ultimately impacting quantum manipulation power October 14th, 2017

Injecting electrons jolts 2-D structure into new atomic pattern: Berkeley Lab study is first to show potential of energy-efficient next-gen electronic memory October 13th, 2017

The secret to improving liquid crystal's mechanical performance: Better lubricating properties of lamellar liquid crystals could stem from changing the mobility of their structural dislocations by adding nanoparticles October 13th, 2017

Possible Futures

Rice U. study: Vibrating nanoparticles interact: Placing nanodisks in groups can change their vibrational frequencies October 16th, 2017

Spin current detection in quantum materials unlocks potential for alternative electronics October 15th, 2017

Quantum manipulation power for quantum information processing gets a boost: Improving the efficiency of quantum heat engines involves reducing the number of photons in a cavity, ultimately impacting quantum manipulation power October 14th, 2017

Injecting electrons jolts 2-D structure into new atomic pattern: Berkeley Lab study is first to show potential of energy-efficient next-gen electronic memory October 13th, 2017

Chip Technology

Spin current detection in quantum materials unlocks potential for alternative electronics October 15th, 2017

Quantum manipulation power for quantum information processing gets a boost: Improving the efficiency of quantum heat engines involves reducing the number of photons in a cavity, ultimately impacting quantum manipulation power October 14th, 2017

Injecting electrons jolts 2-D structure into new atomic pattern: Berkeley Lab study is first to show potential of energy-efficient next-gen electronic memory October 13th, 2017

Rice U. lab surprised by ultraflat magnets: Researchers create atom-thick alloys with unanticipated magnetic properties October 13th, 2017

Quantum Computing

Spin current detection in quantum materials unlocks potential for alternative electronics October 15th, 2017

Quantum manipulation power for quantum information processing gets a boost: Improving the efficiency of quantum heat engines involves reducing the number of photons in a cavity, ultimately impacting quantum manipulation power October 14th, 2017

Quantum communications bend to our needs: By changing the wavelengths of entangled photons to those used in telecommunications, researchers see quantum technology take a major leap forward September 28th, 2017

Physicists develop new recipes for design of fast single-photon gun Physicists develop high-speed single-photon sources for quantum computers of the future September 21st, 2017

Nanoelectronics

Nanometrics Announces Preliminary Results for the Third Quarter of 2017: Quarterly Results Impacted by Delays in Revenue Recognition on Multiple Systems into Japan October 12th, 2017

Seeing the next dimension of computer chips: Researchers image perfectly smooth side-surfaces of 3-D silicon crystals with a scanning tunneling microscope, paving the way for smaller and faster computing devices October 11th, 2017

Columbia engineers invent breakthrough millimeter-wave circulator IC October 6th, 2017

Tungsten offers nano-interconnects a path of least resistance: Crystalline tungsten shows insight and promise in addressing the challenges of electrical interconnects that have high resistivity at the nanoscale October 4th, 2017

Announcements

Rice U. study: Vibrating nanoparticles interact: Placing nanodisks in groups can change their vibrational frequencies October 16th, 2017

Spin current detection in quantum materials unlocks potential for alternative electronics October 15th, 2017

Quantum manipulation power for quantum information processing gets a boost: Improving the efficiency of quantum heat engines involves reducing the number of photons in a cavity, ultimately impacting quantum manipulation power October 14th, 2017

The secret to improving liquid crystal's mechanical performance: Better lubricating properties of lamellar liquid crystals could stem from changing the mobility of their structural dislocations by adding nanoparticles October 13th, 2017

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