2018/09/14
The University of Electro-Communications
Keio University
Highlights of the Research
・We have discovered a previously unknown fundamental limit on the precision of operations on extremely
small objects where quantum mechanics is required.
・A trade-off inequality was derived, showing that to improve operational precision, the energy of the
device performing the operation must fluctuate intensely by a corresponding amount.
・These results are expected to be useful in considering the design of quantum devices used in quantum
computers and the development of nanotechnology, areas that have been actively researched in recent years.
Abstract
A research group consisting of Hiroyasu Tajima, a JSPS Research Fellow at the Graduate School of Informatics and Engineering, The University of Electro-Communications, and Naoto Shiraishi, a visiting researcher, and Professor Keiji Saito from the Faculty of Science and Technology at Keio University, has derived a trade-off relation that indicates the fundamental limit of quantum operations. In situations where one attempts to precisely operate on extremely small objects where the effects of quantum mechanics are significant, they have demonstrated in the form of a rigorous inequality that "achieving high operational precision" and "suppressing the energy fluctuations of the operating device" are incompatible. Attempting to perform an operation with high precision inevitably causes intense energy fluctuations in the device. This inequality signifies that the "uncertainty relation," one of the essences of quantum mechanics, also exists for operations on quantum systems, and it provides the fundamental limit for these operations. The latest findings from quantum information theory were utilized in this derivation. Since the results obtained are valid for general quantum mechanical operations, a wide range of applications can be expected. In particular, these results are considered useful for devising design and development strategies for quantum devices in quantum computers and for nanotechnology.
This research achievement is scheduled to be published in the September 14 issue of the American Physical Society's journal, "Physical Review Letters" (online edition).
For the full press release, please see the link below.