By U.S. Army CCDC Army Research Laboratory Public AffairsJuly 23, 2019
ADELPHI, Md. -- Army scientists have reached a promising milestone in the field of quantum research for improved capabilities in quantum simulation and quantum computation that provide the Soldier a tactical advantage on the battlefield.
Quantum entanglement has the potential for massive data storage and processing, secure communications and quantum, rather than the classically limited, sensing and navigation.
Dr. Q. Sara Quraishi, physicist at the U.S. Army Combat Capabilities Development Command's Army Research Laboratory, along with collaborators at the University of Waterloo, University of California, Berkeley and the Lawrence Berkeley National Laboratory, are the first to propose a numerical technique to achieve two-dimensional physics in a trapped ion system. The proposal uses a simplified laser control technique to increase the utility of linear 1-D ion chains for quantum information studies.
"Trapped ions are excellent candidates for quantum simulation, computing and materials science studies because they have long-lived internal atomic states for quantum information storage and the high-fidelity ion-control has been demonstrated for us in quantum information," Quraishi said. "However, except for a handful of exotic experimental setups, most ions are trapped in linear 1-D chains, limiting their utility to study higher dimensional 2-D or 3-D physics such as quantum entanglement distribution, changes in phases of matter and long or short range interaction physics."
According to Quraishi, given the increasing size in the number of ions the researchers can trap, protocols for higher dimensions are appealing and timely. To meet this need, the researchers must turn off interactions between certain ions in the 1-D chain.
"The ions are physically positioned in a 1-D chain and order themselves with roughly equal spacing, very similar to a 1-D chain of magnetic balls suspended by strings," Quraishi said. "Devising methods to turn on and off interactions between the ions is not easy because they all interact with each other, just like the suspended magnets."
For the case of the ions, careful application of laser fields, as described in the group's work titled "Dynamical Hamiltonian engineering of 2-D rectangular lattices in a one-dimensional ion chain," turns off certain ion-ion interactions so that the result is that the ions only have interactions that would only appear in a 2-D rectangular lattice.
"This protocol is significant because it is considerably simpler than competing methods, which require individual qubit control," Quraishi said. "These results allow for a tractable way to study higher dimension material science in a carefully controlled manner. Better understanding of the fundamental properties of matter can help us engineer devices for enhanced performance and increased capability in applications like sensing and material resiliency."
This research supports the Command, Control, Communications, Intelligence Cross-Functional Team, as it involves creating new avenues for communication and computing.
Namely, quantum entanglement has potential for massive data storage and processing, secure communications and quantum, rather than classically limited, sensing and navigation.
Quraishi said an important feature of this work is that even for increasing ion size (more than 10 ions), the results scale favorably with experimental resources. However, a crucial first step is to demonstrate this protocol for at least four ions.
"ARL's custom fabricate trap can readily trap such a chain of ions," Quraishi said. "In the future, the plan is to apply this hybrid scheme that combines local and global control of the ions to engineer higher-dimensional physics from our linear chain of four ions."
This collaborative effort is overseen by the Army's International Technology Center, which brought together academic-based research and Army Mission aims in quantum science.
"The research topic and approach were based on ideas jointly developed through the Army's interactions with our collaborators," Quraishi said. "By combining expertise from multiple disciplines, we were able to develop an approach to overcome the hurdle of numerically generating higher-dimensional systems given an experimentally tractable 1-D ion trapping configuration."
Quraishi said the future is bright in terms of the potential of this research in the quantum community as well as what it could enable for the Army of the future.
The CCDC Army Research Laboratory (ARL) is an element of the U.S. Army Combat Capabilities Development Command. As the Army's corporate research laboratory, ARL discovers, innovates and transitions science and technology to ensure dominant strategic land power. Through collaboration across the command's core technical competencies, CCDC leads in the discovery, development and delivery of the technology-based capabilities required to make Soldiers more lethal to win our Nation's wars and come home safely. CCDC is a major subordinate command of the U.S. Army Futures Command.