Chemical control of spin–lattice relaxation to discover a room temperature molecular qubit

Abstract

The second quantum revolution harnesses exquisite quantum control for a slate of diverse applications including sensing, communication, and computation. Of the many candidates for building quantum systems, molecules offer both...

Modular Approach to Creating Functionalized Surface Arrays of Molecular Qubits

“…[ 4,29–32 ] The interest toward MSQs has grown quickly and remarkable results concerning the understanding of the relationship between chemical design and quantum properties have been achieved in a short time. [ 33–41 ] It is now clear that long coherence times can be achieved [ 42–45 ] and that multi spin‐level systems can be designed, thanks to which quantum gate operations and quantum error correction algorithms can be implemented even in individual molecules. [ 46–52 ] These studies were conducted mainly on bulk systems such as crystals, powders and solutions.…”

Illuminating Ligand Field Contributions to Molecular Qubit Spin Relaxation via T1 Anisotropy

“…The spin relaxation rate is given by the time constant T 1 . While several S = 1/2 qubits display coherence at room temperature, − optically addressable S = 1 qubits have so far not exceeded 60 K owing to the impact of spin–phonon coupling on T 1 . − As room-temperature quantum applications constitute a key area of interest for molecular qubit systems, this makes it imperative to completely understand the molecular factors controlling the spin relaxation rate.…”

Room-Temperature Quantitative Quantum Sensing of Lithium Ions with a Radical-Embedded Metal–Organic Framework

“…Recent research on molecular qubits based on transition-metal or lanthanide electron spin centers ,− has revealed design rules for achieving millisecond phase memory time , or optical addressability at cryogenic temperature and has established strategies to construct spatially ordered molecular qubit arrays. , Nonetheless, except for a small number of examples with Cu­(II), V­(IV), or Y­(II) as spin centers, − most metal-based molecular qubits do not operate at room temperature due to fast spin–lattice relaxation induced by spin–orbit couplings at the metal sites. ,, In this regard, organic radicals with unpaired electron spins residing on light atoms with negligible spin–orbit coupling, such as carbon, nitrogen, and oxygen, are promising alternatives. When dilute, these can maintain spin coherence at room temperature with microsecond-scale phase memory time. , Although these properties have enabled wide use of organic radicals as spin labels in biological systems and as polarizing agents in dynamic nuclear polarization, organic radicals remain unexplored for quantum sensing.…”

“…29,30 Nonetheless, except for a small number of examples with Cu(II), V(IV), or Y(II) as spin centers, 17−22 most metal-based molecular qubits do not operate at room temperature due to fast spin−lattice relaxation induced by spin−orbit couplings at the metal sites. 20,31,32 In this regard, organic radicals with unpaired electron spins residing on light atoms with negligible spin−orbit coupling, such as carbon, nitrogen, and oxygen, are promising alternatives. When dilute, these can maintain spin coherence at room temperature with microsecond-scale phase memory time.…”