IBM researchers have come up with a technique to view, record and study the behavior of atoms in real time, which could have a long term impact on the way nanoscale chips and devices are built. Recording atomic behaviour in real time was not previously possible, and the breakthrough could help scientists get a better understanding of smaller structures and processing activity at an atomic scale, said Andreas Heinrich, a scientist and researcher at IBM Research.
For example, the breakthrough could help scientists understand how long atoms can hold information, or bits, which could pave the way to build smaller devices. Processing at the atomic level happens in a matter of nanoseconds, and by understanding the atomic behaviour over a time period, scientists could more effectively build nanoscale structures or devices for applications like storage and solar energy, Heinrich said.
For solar energy, the breakthrough will help scientists view in real time the energy conversion of photons to electrons. Scientists will also be able to understand the electronic and magnetic activity of atoms, which could help them pursue smaller storage devices and structures with nanoscale components, Heinrich said. "If you can't see things happen, then you have to infer this from unscientific measurements," he said.
Microscopic objects could be measured in the past, but the new information helps scientists understand how objects dynamically change over relatively short time periods, said Michael Crommie, a professor of physics at the University of California, Berkeley, in a YouTube video describing the technology. "It gives us new handles for getting materials to behave the way we want whether that involves absorbing light or separating charge," Crommie said.
At the heart of the new technique are improvements in the scanning tunnelling microscope (STM), which is like a high speed camera that can record the behaviour of atoms on a nanosecond scale. Magnetic atoms are hit with voltage pulses at specific intervals, and the microscope is able to record the events frame by frame.
Some components were replaced in the STM to make the frame-by-frame recording possible. IBM has had the STM for 20 years, and the earlier components were not capable of recording events in real time. "Since all modifications are external to the actual microscope, we believe that this technique will be widely employed by our research colleagues around the globe," Heinrich said.
The opportunity could change quantum computing, which consists of systems capable of performing massively parallel computation, Heinrich said. At the heart of a quantum computer are quantum bits (qubits), which interact with each other following the laws of quantum mechanics. Those laws apply to the interaction and behavior of matter on atomic and subatomic: proton, neutron and electron levels.
"IBM envisions using individual magnetic atoms on surfaces for this task, using the electron spin of atoms as qubits," Heinrich said.
Atoms are key players in quantum mechanics and in this approach, the STM will be used to position the atoms precisely on a custom-tailored surface. External magnetic fields will be employed to perform the necessary single qubit and multi-qubit operations. The STM will then be used to read out the state of the qubits at the end of the computation. It will be possible to read the state of such an atom on the surface fast enough, Heinrich said.
Quantum computing has been researched for decades, but many problems have popped up around keeping data in a coherent format, making it difficult to run programs or computing tasks. Heinrich said that many key elements still need to be developed to make the technique applicable to quantum computing.
"The inherent advantage of this particular implementation of a quantum computer is the realisation that if we can build and control one qubit, the step to controlling many qubits is rather small, in stark contrast to most other schemes for quantum computation," Heinrich said.
IBM wants to push the limits of engineering, and the breakthrough is fundamental in understanding atoms, IBM's Heinrich said. The company wants to see what happens when a few atoms are put together in small structures. "The IT industry has been shrinking down components... but our worry is to jump to the scale of what will ultimately happen," Heinrich said, referring to IBM's desire to lead in the race to nanoscale computing.