Spin-Lattice Relaxation Decoherence Suppression in Vanishing Orbital Angular Momentum Qubits

Area of Science:

• Quantum spin dynamics
• Electron paramagnetic resonance (EPR) spectroscopy
• Solid-state magnetism

Background:

• Gadolinium(III) ions possess an 8S7/2 ground state with minimal orbital angular momentum.
• Understanding spin dynamics is crucial for quantum information applications.
• Magnetically dilute systems offer insights into fundamental spin properties.

Purpose of the Study:

• To determine the Hamiltonian parameters of the 8S7/2 ground term in Gd(III).
• To measure the phase memory time (Tm) characterizing coherent spin dynamics.
• To investigate the factors limiting spin coherence in magnetically dilute systems.

Main Methods:

• Multifrequency electron paramagnetic resonance (EPR) spectroscopy.
• Utilized oriented single crystals of Gd(III) in a Y(trensal) host matrix (Gd0.004Y0.996(trensal)).
• Analyzed spectral data to extract spin Hamiltonian parameters and phase memory time.

Main Results:

• Successfully determined the Hamiltonian parameters for the 8S7/2 ground term.
• Measured a phase memory time (Tm) of 12 μs at 3 K.
• Observed that Tm is not limited by spin-lattice relaxation due to the insensitivity of the 8S7/2 term to magnetoelastic coupling.

Conclusions:

• The 8S7/2 ground state of Gd(III) exhibits robust spin coherence.
• The long phase memory time is attributed to the vanishing orbital angular momentum, minimizing relaxation pathways.
• These findings are significant for developing quantum technologies utilizing Gd(III) spin systems.