Semi-empirical Haken–Strobl model for molecular spin qubits
Abstract Understanding the physical processes that determine the relaxation T 1 and dephasing T 2 times of molecular spin qubits is critical for envisioned applications in quantum metrology and information processing. Recent spin-echo measurements of solid-state molecular spin qubits have stimulated...
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Published in | New journal of physics Vol. 25; no. 9; pp. 93031 - 93040 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
Bristol
IOP Publishing
01.09.2023
|
Subjects | |
Online Access | Get full text |
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Summary: | Abstract
Understanding the physical processes that determine the relaxation
T
1
and dephasing
T
2
times of molecular spin qubits is critical for envisioned applications in quantum metrology and information processing. Recent spin-echo measurements of solid-state molecular spin qubits have stimulated the development of quantum mechanical models for predicting intrinsic qubit timescales using first-principles electronic structure methods. We develop an alternative semi-empirical approach to construct Redfield quantum master equations for molecular spin qubits using a stochastic Haken–Strobl theory for a central spin with fluctuating gyromagnetic tensor due to spin-lattice interaction and fluctuating local magnetic field due to interactions with lattice spins. Using two vanadium-based spin qubits as case studies, we compute qubit population and decoherence times as a function of temperature and magnetic field, using a bath spectral density parametrized with a small number of
T
1
measurements. The theory quantitatively agrees with experimental data over a range of conditions beyond those used to parameterize the model, demonstrating the generalization potential of the method. The ability of the model to describe the temperature dependence of the ratio
T
2
/
T
1
is discussed and possible applications for designing novel molecule-based quantum magnetometers are suggested. |
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Bibliography: | NJP-116404.R1 |
ISSN: | 1367-2630 1367-2630 |
DOI: | 10.1088/1367-2630/acf2bd |