IBM Claims Breakthrough in Carbon Nanotube Research

IBM researchers are claiming a significant breakthrough in the emerging field of nanotechnology that could change the way engineers and the IT industry think about the development of microprocessors.

In a paper published in the Nature Nanotechnology journal Aug. 25, IBM researchers describe how they integrated and controlled an electrically driven, nanoscale light emitter that engineers built around a single carbon nanotube.

A carbon nanotube is a series of tiny tubes of rolled-up carbon hexagons. Carbon nanotubes could be used in new types of transistors—the tiny on/off switches used to transmit electrical signals inside processors.

The IBM paper describes this development as a critical first step in the future development of nanotube-based integrated electronic and nanophotonic devices. These developments in nanotechnology have the potential to change the way companies such as IBM and Intel boost the performance of future generations of microprocessors and computer memory.

Nanotechnology is an emerging field of research that looks to shrink already small components to an even small size. The field of nanotechnology involves working with materials that are 100 nanometers or smaller, or just a fraction of the width of a human hair.

The ability to decrease the size of silicon-based transistors, which in turn allows chip makers to boost their chips' performance by packing more transistors into each processor, will eventually end. When this happens, IBM, Intel and other chip makers will have to invest in new technologies. This is where carbon nanotubes, nanowires or other materials and technologies could make a difference.

In the new IBM research paper, scientists describe how they were able to combine a single nanotube-based field effect transistor, or FET, with a pair of tiny, nanomirrors on one chip. This type of integration allowed researchers to control the optical emissions from a nanotube. In turn, IBM researchers were able to control the wavelength of the optical emissions, the spectral and spatial distributions of the emitted light and the efficiency of the emissions.

While lasers have been used before in new types of chip development, the IBM research showed that lasers can also be used at the nanolevel, which could pave the way toward nanophotonics. The goal of nanophotonics is to build integrated circuits that manipulate light signals to transmit data the same way electrical signals transmit data in traditional silicon-based microprocessors.

The developments that IBM describes in the Nature Nanotechnology article builds on several other breakthroughs the company’s researchers have announced this year. In March, engineers detailed a new nanophotonic silicon broadband switch that will route optical pulse signals within a microprocessor from a transmitting core to a receiving core.

While IBM has published several papers this year in the field of nanotechnology, it’s not the only IT company studying ways to create new processors from the technology.

In addition to IBM, HP Labs—the research division of Hewlett-Packard—is working on ways to create new types of nanoscale devices. In April, HP researchers detailed their work into finding the fourth fundamental circuit element within electrical engineering, called a memristor, short for memory resistor. This is expected to give researchers new insight in the development of different types of computer memory.

At the recent Intel Developer Forum in San Francisco, Intel CTO Justin Rattner detailed his company’s work in the field of photonics—the ability to send data across pulses of light that will eventually replace copper wiring. This research, and Intel’s investment in funding new developments, also has the potential to make nanoscale devices possible.

While processors that use light to transmit data from one point to another have applications in the world of high-performance computing and large-scale data centers, Rattner said that Intel wants to first put the technology in desktops, which will show the practical side of the technology and also help bring the price down to a reasonable level.

If Intel succeeds, then it could mean that photonics and nanophotonics could lead to whole new ways of creating chips that are powerful but offer better battery life for small devices, such as notebook PCs, and wireless and mobile devices, such as cell phones.

It is important to keep in the mind that while all these developments are ongoing, nanotechnology will probably not replace traditional silicon in chip development anytime soon. Intel and IBM are each still using more traditional silicon technology to build the next generation of both 32-nm and 22-nm microprocessors.

Besides IBM, HP and Intel, the field of nanotechnology has garnered attention from the United States government. In June, the U.S. House of Representatives approved new legislation to reauthorize federal nanotechnology research programs.