Modular Approach to Creating Functionalized Surface Arrays of Molecular Qubits

Abstract

The quest for developing quantum technologies is driven by the promise of exponentially faster computations, ultrahigh performance sensing, and achieving thorough understanding of many‐particle quantum systems. Molecular spins are excellent qubit candidates because they feature long coherence times, are widely tunable through chemical synthesis, and can be interfaced with other quantum platforms such as superconducting qubits. A present challenge for molecular spin qubits is their integration in quantum devices, which requires arranging them in thin films or monolayers on surfaces. However, clear proof of the survival of quantum properties of molecular qubits on surfaces has not been reported so far. Furthermore, little is known about the change in spin dynamics of molecular qubits going from the bulk to monolayers. Here, a versatile bottom‐up method is reported to arrange molecular qubits as functional groups of self‐assembled monolayers (SAMs) on surfaces, combining molecular self‐organization and click chemistry. Coherence times of up to 13 µs demonstrate that qubit properties are maintained or even enhanced in the monolayer.

Triptycene-Based Self-Assembled Monolayer as a Template for Successive Click Reactions

“…As such module, we take 10-ethynyl-decorated 1,8,13-trimercaptomethyltriptycene (EtTripS; see Figure ), which can be obtained from EtTripSAc (Scheme ). The terminal ethynyl moiety of this molecule is useful for functionalization using cross-coupling reactions and can potentially participate in click reaction with azide-decorated functional groups. , Analogous reactions were demonstrated for a variety of template SAMs, mostly with azide-terminated molecules and ethynyl-decorated substituents − and also other way around, − similar to the present case. Here, as a representative test, we apply click reaction to the EtTripS template assembled on Au(111), a most frequently used substrate for the SAM fabrication, relevant as well as an electrical contact material in organic and molecular electronics.…”

Lanthanide molecular nanomagnets as probabilistic bits

“…Each p-bit could consist of a large molecu-lar ensemble rather than a single molecule, and indeed there are rapid advances both in the interaction of thin ensembles of spins with electronic circuits 39,40 and in chemical paths for protecting monolayers of spins from disruption by a substrate. 41 Working with a monolayer of M molecules would have the following major implications:…”

Fabrication of multi-functional molecular tunnelling junctions by click chemistry

“…Using click chemistry, McCreery et al 20 fabricated bilayer SAMs of ferrocene in high yield. Besides, Slageren et al 12 used click chemistry to arrange molecular qubits as functional groups to avoid a laid-down orientation by direct deposition. Crivillers et al 21 combined radical chemistry with click chemistry on a platform of molecular self-assembled monolayers to synthesize multistate electrochemical switches by surface modification.…”

“…In the meantime, the self-assembly of molecules with different structures forming stable and well-organized electrical circuits is considered to be another huge challenge, limited by state-of-the-art nanofabrication technology. Many factors, such as the roughness of the substrates, 9 anchoring groups, 10 types of backbones 11 and terminal functional groups 12 simultaneously influence the packing process. Therefore, it is necessary to develop a method that advances the traditional protocol for the synthesis and fabrication of molecular junctions.…”