A concentrated array of copper porphyrin candidate qubits

Area of Science:

• Quantum Information Science
• Materials Chemistry
• Solid-State Physics

Background:

• Atomically precise qubit arrays are crucial for quantum information science.
• Metal-organic frameworks (MOFs) offer a tunable platform for designing functional materials.
• Developing stable and scalable qubit architectures remains a significant challenge.

Purpose of the Study:

• To synthesize and characterize a novel metal-organic framework for creating an array of qubit candidates.
• To investigate the quantum coherence properties of these qubits at elevated temperatures.
• To understand the spin dynamics and relaxation mechanisms within the qubit array.

Main Methods:

• Synthesis of a copper(II) variant of the porphyrinic metal-organic framework PCN-224.
• Pulse-electron paramagnetic resonance (EPR) measurements to assess spin coherence and Rabi oscillations.
• Spin-lattice relaxation (T1) measurements using pulse-EPR and alternating current (ac) magnetic susceptibility.

Main Results:

• Successful synthesis of PCN-224 with qubits spaced at 13.6 Å intervals.
• Demonstrated spin coherence up to 80 K in a fully spin-concentrated framework.
• Identified distinct vibrational environments influencing spin dynamics and relaxation.

Conclusions:

• The study establishes a synthetic route to precisely positioned qubit arrays using MOFs.
• The demonstrated spin coherence at 80 K is a significant advancement for practical quantum systems.
• This work provides a foundation for designing and optimizing qubit networks for quantum technologies.