2019 News

Zhang Studies Quantum Information Science with DOE Grant in Collaboration with FSU Professor

Jason Zhang - DOE Grant

Jianyuan (Jason) Zhang will share grant funding from the Department of Energy (DOE) in collaboration with Professor Stephen Hill of Florida State University, for a proposal titled, “A Route to Molecular Quantum Technologies Using Endohedral Metallofullerenes.”

This project was part of the DOE’s targeted research in materials and chemistry to advance the important emerging field of Quantum Information Science (QIS). The three-year grant, totaling $1.26M, will allow the researchers at Florida State University and Rutgers University to investigate magnetic metallofullerene and their derivatives with high-field pulse EPR approaches for a bottom-up molecular design of quantum materials.

Read the selected abstract below:

"In the search for physical realizations of the basic units for practical quantum computing (quantum bits or qubits), the bottom-up molecular approach is highly promising. This project focuses on fundamental studies of a unique class of metal-organic hybrid molecules, so-called endohedral metallofullerenes (EMFs), in which quantum information can be encoded into the magnetic (spin) states associated with lanthanide (Ln) atoms that are encapsulated within robust carbon cages (fullerenes). This approach promises significant advantages over other current magnetic qubit targets based on inorganic molecules and solids. First and foremost, the fullerene cage provides a rigid environment devoid of elements that possess magnetic nuclei (the 12C nucleus is non-magnetic), thereby protecting the encapsulated atoms from well-known and stubborn noise sources – random vibrations and fluctuating magnetic fields due to nearby nuclei – that can easily erase fragile quantum information states. Equally important is the focus on carbon-based molecules, which opens up the vast toolbox of organic molecular chemistry. This will allow for large-scale synthesis of chemically identical species, with exquisite control over the quantum information states of the associated endohedral Ln atoms. Meanwhile, chemical functionalization of the periphery of the EMF cage will provide potential routes to scaling-up into more complex quantum circuits via molecular self-assembly, and possibilities for rapid optical encoding and read-out of quantum information via attachment of optically active organic groups. Finally, the quantum computational resources that are attainable within a single EMF molecule containing multiple Ln atoms (up to three) with large magnetic moments (e.g. Gd3+) are expected to be considerable in comparison to inorganic transition metal counterparts. Therefore, the project aims to demonstrate the implementation of simple quantum algorithms on individual Ln EMF qudits (the generalization to base d of a qubit), something that is not possible on a single molecular qubit. Synthetic efforts aim to: (1) realize accurate and targeted tuning of the magnetic quantum states of encapsulated Ln ions, thus enabling precise, highfidelity qubit manipulation using advanced microwave magnetic resonance techniques; and (2) enable responsiveness to other external stimuli (light, current, etc.) for localized/selective qubit readout and control. The project will leverage unique electron spin resonance (ESR) instrumentation available at the US National High Magnetic Field Laboratory (NHMFL), both for precisely characterizing the magnetic states of candidate Ln-EMF molecules, and for demonstrating practical quantum logic operations. Collectively, these efforts will lead to a seamless feedback loop encompassing structural design, chemical synthesis, spectroscopic characterization, and quantum operation, to establish fundamental understanding of the design rules for EMF-based molecular qubits/qudits with desired properties, paving the way towards next-generation quantum technologies."