Molecular qubits based on potentially nuclear-spin-free nickel ions

Area of Science:

• Quantum computing
• Molecular magnetism
• Materials science

Background:

• Nuclear spins in molecular qubits can cause quantum state leakage, hindering quantum algorithm performance.
• Longest coherence times achieved so far are with nuclear-spin-carrying central ions.

Purpose of the Study:

• To present novel molecular qubits based on potentially nuclear spin-free Ni(III) complexes.
• To evaluate the coherence times and robustness of these new molecular qubit candidates.

Main Methods:

• Synthesis and characterization of two novel Ni(III) complexes: (d20-PPh4)[Ni(mnt)2] (Ni-mnt) and (HNEt3)[Ni(dip)2] (Ni-dip).
• Measurement of coherence times for the synthesized molecular qubits at 7 K.

Main Results:

• The Ni-mnt complex exhibited a coherence time of up to 38.7 μs at 7 K.
• The Ni-dip complex, with a functionalized ligand, showed a reduced coherence time (factor of four), demonstrating robustness.
• Monoanionic Ni-dithiolene complexes were identified as promising building blocks.

Conclusions:

• Novel nuclear spin-free Ni(III) molecular qubits offer an alternative to nuclear-spin-based systems.
• These Ni-dithiolene complexes demonstrate robustness and potential for developing molecular qubit gates.
• The findings pave the way for improved quantum computing applications using molecular materials.