Spin Echo and Coherence Time of Cr₇Mn Nanomagnet

Molecular nano-magnets (MNMs) are one of the promising systems for use as qubits for reduced decoherence thanks to the versatile tunability of the spin environment and unmatched scalability. Cr₇Mn is in a family of heterometallic rings where avoided level crossing presents at zero magnetic field. This makes the magnet insensitive to the fluctuation of the field hence increases the coherence. We measured T₂ and observed it to peak around zero field. We also saw Electron Spin Echo Envelope Modulation (ESEEM) outside of clock transition resulting from the coupling between spin and nucleus. This could provide an additional mechanism that preserves the information away from clock transition. Combined with the CPMG pulse sequence, ESEEM oscillations can be demodulated and have long coherence time. Dimers of coupled Cr₇Mn molecules with different transition frequencies could be addressed individually with radio-frequency radiation, and the coupling between the two qubits could lead to new properties and applications.