via University of Melbourne
Quantum computers could be constructed cheaply and reliably using a new technique perfected by a University of Melbourne-led team that embeds single atoms in silicon wafers, one-by-one, mirroring methods used to build conventional devices, in a process outlined in an Advanced Materials paper.
The new technique – developed by Professor David Jamieson and co-authors from UNSW Sydney, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Leibniz Institute of Surface Engineering (IOM), and RMIT – can create large scale patterns of counted atoms that are controlled so their quantum states can be manipulated, coupled and read-out.
Lead author of the paper, Professor Jamieson said his team’s vision was to use this technique to build a very, very large-scale quantum device.
“We believe we ultimately could make large-scale machines based on single atom quantum bits by using our method and taking advantage of the manufacturing techniques that the semiconductor industry has perfected,” Professor Jamieson said.
The technique takes advantage of the precision of the atomic force microscope, which has a sharp cantilever that “touches” the surface of a chip with a positioning accuracy of just half a nanometre, about the same as the spacing between atoms in a silicon crystal.
The team drilled a tiny hole in this cantilever, so that when it was showered with phosphorus atoms one would occasionally drop through the hole and embed in the silicon substrate.
The key was knowing precisely when one atom – and no more than one – had become embedded in the substrate. Then the cantilever could move to the next precise position on the array.
The team discovered that the kinetic energy of the atom as it ploughs into the silicon crystal and dissipates its energy by friction can be exploited to make a tiny electronic “click”.
Professor Jamieson said the team could “hear” the electronic click as each atom dropped into one of the 10,000 sites in the prototype device.
“One atom colliding with a piece of silicon makes a very faint click, but we have invented very sensitive electronics used to detect the click, it’s much amplified and gives a loud signal, a loud and reliable signal,” Professor Jamieson said.
“That allows us to be very confident of our method. We can say, ‘Oh, there was a click. An atom just arrived. Now we can move the cantilever to the next spot and wait for the next atom,’” Professor Jamieson said.
Until now, implanting atoms in silicon has been a haphazard process, where a silicon chip gets showered with phosphorus which implants in a random pattern, like raindrops on a window.
Co-author, Scientia Professor Andrea Morello from the University of New South Wales said the new technique embedded phosphorus ions, precisely counting each one, in a silicon substrate creating a qubit “chip”, which can then be used in lab experiments to test designs for large scale devices.
“This will allow us to engineer the quantum logic operations between large arrays of individual atoms, retaining highly accurate operations across the whole processor,” Professor Morello said.
“Instead of implanting many atoms in random locations and selecting the ones that work best, they will now be placed in an orderly array, similar to the transistors in conventional semiconductors computer chips.”
First author, University of Melbourne’s Dr Alexander (Melvin) Jakob said highly specialised equipment was used for the collaboration.
“We used advanced technology developed for sensitive x-ray detectors and a special atomic force microscope originally developed for the Rosetta space mission along with a comprehensive computer model for the trajectory of ions implanted into silicon, developed in collaboration with our colleagues in Germany,” Dr Jakob said.
“With our Centre partners, we have already produced ground-breaking results on single atom qubits made with this technique, but the new discovery will accelerate our work on large-scale devices.”
Practical implications of quantum computers include new ways of optimising timetable and finances, unbreakable cryptography and computational drug design, and potentially the rapid development of vaccines.
The Latest Updates from Bing News & Google News
Go deeper with Bing News on:
Silicon quantum computers
- University of Toronto: Quantum innovation advances low-cost alternative solar technology
A team of researchers from the University of Toronto’s Faculty of Applied Science & Engineering has leveraged quantum mechanics to optimize the active layer within a device known as an inverted perovs ...
- IBM seeks to deliver 4,000+ Qubit system for Quantum computing era
IBM seeks to deliver 4,000+ Qubit system for Quantum computing era - In yet another push to its quantum computing dream, IBM has announced a new roadmap to deliver a massive ...
- Sydney quantum computing startup splits into two companies
Startup Silicon Quantum Computing (SQC) has sold intellectual property to the University of New South Wales and Allectus Capital, to form a spin off company dedicated to qubit fabrication technology.
- Scientists at VTT Develop SiPh Technology Likely to Help a Broad Range of Applications
VTT is Finland’s major developer of silicon photonics. Silicon chips’ fast speed, energy efficiency, and minuscule size can help a wide range of applications, from medical to autonomous transportation ...
- Quantum Data at the Atom's Heart (VIDEO)
A team of Australian engineers at the University of New South Wales in Sydney has demonstrated a quantum bit based on the nucleus of a single atom in silicon, promising dramatic improvements for data ...
Go deeper with Google Headlines on:
Silicon quantum computers
Go deeper with Bing News on:
Large-scale quantum computers
- IBM unveils new roadmap for quantum computing supremacy
As the US and China continue to compete in technology superiority, quantum computing is one field that both countries may eventually end up working together. Make no mistake, both countries are still ...
- IBM’s massive ‘Kookaburra’ quantum processor might land in 2025
To get to its 2025 goal of a 4,000 qubit plus chip, IBM has micro-milestones it wants to hit on both the hardware and software side.
- IBM lays out plans for 4,000-qubit chips in updated quantum computing roadmap
IBM Corp. today announced a new roadmap that it says will usher in a new era of large-scale and practical quantum computing. The plan involves creating new modular architectures and networking systems ...
- We May Finally Soon Have The Ideal Building Block For Quantum Computers
We already have quantum computers of a sort, but at the moment they're not practical or reliable or large-scale enough to fully realize the massive potential of the technology.
- IBM Expands Access To Quantum Computing
IBM updated its offerings in quantum computing and added new managed quantum systems for select international clients.