Theoretical evaluation of [V$^{IV}$({\alpha}-C$_3$S$_5$)]${^2-}$ as nuclear-spin sensitive single-molecule spin transistor

TL;DR

This paper theoretically evaluates the potential of a vanadium-based molecular spin transistor for nuclear-spin detection in quantum computing, demonstrating its stability and conductance properties through detailed modeling.

Contribution

It introduces a theoretical framework for using a vanadium tris-dithiolate complex as a nuclear-spin sensitive single-molecule spin transistor, extending prior work beyond terbium complexes.

Findings

Transport channel does not overlap with occupied spin orbitals.

The molecule's spin states may persist during conduction.

The methodology is validated on related vanadium complexes.

Abstract

In a straightforward application of molecular nanospintronics to quantum computing, single-molecule spin transistors can be used to measure and control nuclear spin qubits. A jump in the conductance occurs when the electronic spin inverts its polarization, and this happens at a so-called anticrossing between energy levels, which in turn only takes place at a specific magnetic field determined by the nuclear spin state. So far, this procedure has only been implemented for the terbium(III) bis(phthalocyaninato) complex. Here we explore theoretically whether a similar behavior is expected for a highly stable molecular spin qubit, the vanadium tris-dithiolate complex [V$^{IV}$({\alpha}-C$_3$S$_5$)]${^2-}$. We consider such molecule sandwiched into a two-terminal device and determine the spin-dependent conductance. We verify that the transport channel at minimal bias voltage does not overlap with the occupied spin orbitals, indicating that the spin states may survive in the conduction regime. We estimate some physical parameters to guide the experiments, and verify the robustness of the theoretical methodology by applying it to two chemically related vanadium complexes.