Quantum computers are in theory capable of simulating the interactions of molecules at a level of detail far beyond the capabilities of even the largest supercomputers today. Such simulations could revolutionize chemistry, biology and material science, but the development of quantum computers has been limited by the ability to increase the number of quantum bits, or qubits, that encode, store and access large amounts of data.
In a paper appearing this week in the Journal of Applied Physics, from AIP Publishing, a team of researchers at Georgia Tech Research Institute and Honeywell International have demonstrated a new device that allows more electrodes to be placed on a chip — an important step that could help increase qubit densities and bring us one step closer to a quantum computer that can simulate molecules or perform other algorithms of interest.
“To write down the quantum state of a system of just 300 qubits, you would need 2^300 numbers, roughly the number of protons in the known universe, so no amount of Moore’s Law scaling will ever make it possible for a classical computer to process that many numbers,” said Nicholas Guise, who led the research. “This is why it’s impossible to fully simulate even a modest sized quantum system, let alone something like chemistry of complex molecules, unless we can build a quantum computer to do it.”
While existing computers use classical bits of information, quantum computers use “quantum bits” or qubits to store information. Classical bits use either a 0 or 1, but a qubit, exploiting a weird quantum property called superposition, can actually be in both 0 and 1 simultaneously, allowing much more information to be encoded. Since qubits can be correlated with each other in a way that classical bits cannot, they allow a new sort of massively parallel computation, but only if many qubits at a time can be produced and controlled. The challenge that the field has faced is scaling this technology up, much like moving from the first transistors to the first computers.
Creating the Building Blocks for Quantum Computing
One leading qubit candidate is individual ions trapped inside a vacuum chamber and manipulated with lasers. The scalability of current trap architectures is limited since the connections for the electrodes needed to generate the trapping fields come at the edge of the chip, and their number are therefore limited by the chip perimeter.
The GTRI/Honeywell approach uses new microfabrication techniques that allow more electrodes to fit onto the chip while preserving the laser access needed.
The team’s design borrows ideas from a type of packaging called a ball grid array (BGA) that is used to mount integrated circuits. The ball grid array’s key feature is that it can bring electrical signals directly from the backside of the mount to the surface, thus increasing the potential density of electrical connections.
The researchers also freed up more chip space by replacing area-intensive surface or edge capacitors with trench capacitors and strategically moving wire connections.
The space-saving moves allowed tight focusing of an addressing laser beam for fast operations on single qubits. Despite early difficulties bonding the chips, a solution was developed in collaboration with Honeywell, and the device was trapping ions from the very first day.
The team was excited with the results. “Ions are very sensitive to stray electric fields and other noise sources, and a few microns of the wrong material in the wrong place can ruin a trap. But when we ran the BGA trap through a series of benchmarking tests we were pleasantly surprised that it performed at least as well as all our previous traps,” Guise said.
Working with trapped ion qubits currently requires a room full of bulky equipment and several graduate students to make it all run properly, so the researchers say much work remains to be done to shrink the technology. The BGA project demonstrated that it’s possible to fit more and more electrodes on a surface trap chip while wiring them from the back of the chip in a compact and extensible way. However, there are a host of engineering challenges that still need to be addressed to turn this into a miniaturized, robust and nicely packaged system that would enable quantum computing, the researchers say.
In the meantime, these advances have applications beyond quantum computing.
The Latest on: Quantum Computer
via Google News
The Latest on: Quantum Computer
- Closing Quantum Cybersecurity Gap an Imperative: Industry and Government to Warn at Toronto Quantum Summit on April 18, 2019 at 3:00 am
"A very serious gap exists today in our ability to encrypt data and ensure privacy, against a future quantum computer that will have the ability to crack our existing encryption systems in the blink ... […]
- Quantum Computing 101: A Beginner’s Guide to the Mind-Bending New Technology on April 18, 2019 at 2:13 am
Have you heard the term "quantum computing" thrown around thousands of times over the years, without having a clue what it means? Fear not. You are in good company. Classical or traditional computing ... […]
- Harvard spinoff Zapata Computing raises $21M to develop quantum software on April 17, 2019 at 10:40 am
A consortium of venture investors is making a moonshot bet on Zapata Computing Inc., a startup developing software for quantum computers. Cambridge, Massachusetts-based Zapata today said that it ... […]
- Why HPE Abandoned Quantum Computing Research on April 17, 2019 at 10:13 am
Like all major server-focused tech companies, HPE has been keeping close tabs on where quantum computing might go in the future. And while some of the company’s research leads see a bright future on a ... […]
- UofL, IBM create academy to teach AI, IoT, cybersecurity, quantum computing on April 17, 2019 at 10:12 am
University of Louisville President Neeli Bendapudi, center, poses with dignitaries after announcing a new partnership with IBM. | Photo by Boris Ladwig “The future is not going to leave the good ... […]
- World-record quantum computing on April 17, 2019 at 8:28 am
A world-record result in reducing errors in semiconductor electron 'spin qubits', a type of building block for quantum computers, has been achieved. A world-record result in reducing errors in ... […]
- Improving quantum computers on April 17, 2019 at 7:36 am
For decades, experts have predicted that quantum computers will someday perform difficult tasks, such as simulating complex chemical systems, that can't be done by conventional computers. […]
- Quantum Computing Startup Zapata Computing Raises $21 Million in Series A Financing on April 17, 2019 at 6:43 am
Quantum computing startup Zapata Computing (www.zapatacomputing.com) today announced it has raised $21 million in Series A financing. Led by Comcast Ventures and Prelude Ventures, the round includes ... […]
- World-record quantum computing result for Sydney teams on April 17, 2019 at 6:43 am
A world-record result in reducing errors in semiconductor 'spin qubits', a type of building block for quantum computers, has been achieved using the theoretical work of quantum physicists at the ... […]
- This Startup Just Raised $21 Million To Bring Quantum Computing To Enterprise Applications on April 17, 2019 at 6:00 am
Zapata Computing, a quantum computing software startup that spun out of Harvard, announced Wednesday that it has raised $21 million in a series A round. The round was led by Prelude Ventures and ... […]
via Bing News