Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Computational Insights into Electronic Excitations, Spin-Orbit Coupling
  Effects, and Spin Decoherence in Cr(IV)-based Molecular Qubits   The great success of point defects and dopants in semiconductors for quantum
information processing has invigorated a search for molecules with analogous
properties. Flexibility and tunability of desired properties in a large
chemical space have great advantages over solid-state systems. The properties
analogous to point defects were demonstrated in Cr(IV)-based molecular family,
Cr(IV)(aryl)$_4$, where the electronic spin states were optically initialized,
read out, and controlled. Despite this kick-start, there is still a large room
for enhancing properties crucial for molecular qubits. Here we provide
computational insights into key properties of the Cr(IV)-based molecules aimed
at assisting chemical design of efficient molecular qubits. Using the
multireference ab-initio methods, we investigate the electronic states of
Cr(IV)(aryl)$_4$ molecules with slightly different ligands, showing that the
zero-phonon line energies agree with the experiment, and that the excited
spin-triplet and spin-singlet states are highly sensitive to small chemical
perturbations. By adding spin-orbit interaction, we find that the sign of the
uniaxial zero-field splitting (ZFS) parameter is negative for all considered
molecules, and discuss optically-induced spin initialization via non-radiative
intersystem crossing. To understand electron spin decoherence, we quantify
hyperfine coupling to the $^{53}$Cr nuclear spin and to the $^{13}$C and $^1$H
nuclear spins. We show that the splitting or broadening of the electronic spin
sub-levels induced by these hyperfine interactions decreases by an order of
magnitude when the molecules have a substantial transverse ZFS parameter. This
feature is applicable to other integer-spin molecules in order to significantly
reduce spin decoherence.

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The categories of this paper are: hep-ex
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The categories of this paper are: chao-dyn
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The categories of this paper are: mtrl-th
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The categories of this paper are: gr-qc
31
The categories of this paper are: ao-sci
28
The categories of this paper are: alg-geom
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The categories of this paper are: cmp-lg
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The categories of this paper are: econ
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The categories of this paper are: comp-gas
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The categories of this paper are: dg-ga
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The categories of this paper are: q-alg
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The categories of this paper are: nucl-ex
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The categories of this paper are: cs
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The categories of this paper are: math-ph
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The categories of this paper are: supr-con
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The categories of this paper are: nucl-th