Spin coherence and magnetization dynamics of TMA₂[KCo_1-Fe(CN)₆] toward coordination-framework spin qubits

Area of Science:

• Quantum computing materials science
• Molecular magnetism
• Coordination chemistry

Background:

• S = 1/2 coordination-frameworks are emerging as potent qubit candidates.
• Understanding magnetization dynamics and spin coherence is crucial for qubit development.

Purpose of the Study:

• To investigate the qubit potential of the CN-based coordination framework TMA₂[KCo_1-Fe(CN)₆].
• To explore the magnetic dilution effects of Fe(III) in a Co(III)-based diamagnetic analogue.

Main Methods:

• Alternating-current (AC) susceptibility measurements to study magnetic relaxation.
• Pulsed Electron Paramagnetic Resonance (EPR) to assess spin coherence.
• Magnetic dilution of Fe(III) in TMA₂[KCo(CN)₆] framework.

Main Results:

• Slow magnetic relaxation observed, following phonon-bottleneck and Raman processes.
• A magnetic relaxation time (τ) of 0.3 s at 1.8 K (2% Fe).
• A coherence duration of 1 μs at 4 K (0.1% Fe) and observed Rabi oscillations.

Conclusions:

• TMA₂[KCo_1-Fe(CN)₆] demonstrates significant potential as a qubit.
• The material can be placed in superpositions of distinct Ms states, essential for qubit operation.