WASHINGTON, July 24 (Xinhua) -- An international team led by an Australian physicist demonstrated the world's first multi-qubit quantum chemistry calculation based on a system of trapped ions.
A study published on Tuesday in the journal Physical Review X of the American Physical Society described the hardware platform, potentially offering an effective way to model chemical bonds and reactions using quantum computers.
"Even the largest supercomputers are struggling to model accurately anything but the most basic chemistry. Quantum computers simulating nature, however, unlock a whole new way of understanding matter," said Cornelius Hempel from University of Sydney.
"They will provide us with a new tool to solve problems in materials science, medicine and industrial chemistry using simulations," said Hempel.
Since the quantum computing is still in its infancy, it remains unclear what problems these devices will be most effective at solving, but most experts agree that quantum chemistry is going to be one of the first "killer apps" of this emergent technology.
Quantum chemistry is the science of understanding the complicated bonds and reactions of molecules using quantum mechanics, by which scientists expect to unlock lower-energy pathways for chemical reactions, allowing the design of new catalysts.
Other possible applications include the development of organic solar cells and better batteries through improved materials and using new insights to design personalized medicines, according to the study.
In collaboration with colleagues at the Institute for Quantum Optics and Quantum Information (IQOQI) in Austria, Hempel used just four qubits on a 20-qubit device to run algorithms to simulate the energy bonds of molecular hydrogen and lithium hydride.
These relatively simple molecules are chosen as they are well understood and can be simulated using classical computers, allowing scientists to check the results provided by the quantum computers under development.
"This is an important stage of the development of this technology as it is allowing us to set benchmarks, look for errors and plan necessary improvements," said Hempel.
Instead of making the most accurate or largest simulation, Hempel's work focused on what can go wrong in a promising quantum-classical hybrid algorithm known as variational quantum eigensolver or VQE.
By looking at different ways to encode the chemistry problem, the researchers are after ways to suppress errors in the current imperfect quantum computers that undermine near-term usefulness of those machines.
IQOQI professor Rainer Blatt and Alan Aspuru-Guzik from the University of Toronto co-authored the paper.
"Quantum chemistry is an example where the advantages of a quantum computer will very soon become apparent in practical applications," said Blatt.
