(ScienceDaily) Quantum computers promise to solve certain computational problems exponentially faster than any classical machine. “A particularly promising application is the solution of quantum many-body problems utilizing the concept of digital quantum simulation,” says Markus Heyl from Max Planck Institute for the Physics of Complex in Dresden, Germany. “Such simulations could have a major impact on quantum chemistry, materials science and fundamental physics.”
Within digital quantum simulation the time evolution of the targeted quantum many-body system is realized by a sequence of elementary quantum gates by discretizing time evolution, called Trotterization. Heyl–together with Peter Zoller from the Department of Experimental Physics at the University of Innsbruck and the Institute of Quantum Optics and Quantum Communication at the Austrian Academy of Sciences and Philipp Hauke from the Kirchhoff Institute for Physics and the Institute for Theoretical Physics at the University of Heidelberg showed in a recent paper in Science Advances quantum localization-by constraining the time evolution through quantum interference-strongly bounds these errors for local observables.
“Digital quantum simulation is thus intrinsically much more robust than what one might expect from known error bounds on the global many-body wave function,” Heyl says. This brings digital quantum simulation for classically challenging quantum many-body problems within reach for current day quantum devices.

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