A Synthetic Two‐Spin Quantum Bit: g‐Engineered Exchange‐Coupled Biradical Designed for Controlled‐NOT Gate Operations

Abstract

Ein Quantengatter: Ein System aus zwei gekoppelten Elektronenspins, das für einfache Quantencomputer‐Operationen verwendet werden kann, wurde durch Cokristallisation des Diradikals 1 mit einem isomorphen Wirtmolekül hergestellt. Die beiden schwach austauschgekoppelten Quantenbits – Ziel‐Qubit (blau) und Kontroll‐Qubit (rot) – bilden ein System aus vier Elektronenspinzuständen, in dem der Elektronenspin‐Übergang mit zwei schwarzen Pfeilen markiert ist.

g‐Engineering in Hybrid Rotaxanes To Create AB and AB2 Electron Spin Systems: EPR Spectroscopic Studies of Weak Interactions between Dissimilar Electron Spin Qubits

“…Takui and co-workers have done this using elegant organic chemistry, and have reported the operation of the CNOT gate using such an approach. [2] Here we show how similar g-engineering can be achieved using coordination chemistry of 3d-metal cages.…”

“…This is the basis of Takui and co-workers' "g-engineering" approach to 7 construct a CNOT gate with dissimilar organic radicals, [2] and towards Lloyd's proposal of periodic (ABC) n arrays using inequivalently orientated metal ions in helicates.…”

“…Proposed molecular spin qubits include organic radicals, [2] simple coordination complexes, [7] high-spin [1] and low-spin clusters, [3][4][5] and 4f ions. [6] One challenge is to bring together ensembles of such qubits, and particularly to bring together qubits with different electronic g-factors, so called g-engineering, [2,6] which would allow the qubits to be addressed individually and controllably within a complex molecule. Takui and co-workers have done this using elegant organic chemistry, and have reported the operation of the CNOT gate using such an approach.…”

“…Hybrid [2]rotaxanes and pseudo-rotaxanes are reported where the magnetic interaction between dissimilar spins is controlled to create AB and AB 2 electron spin systems, allowing independent control of weakly interacting S = 1 / 2 centers Several groups have proposed the idea that molecules could be used as electron spin qubits. [1][2][3][4][5][6] Molecular qubits can be designed such that phase memory times (T m ) approach other solid state electron spin technologies, [7] and have the advantage of being functionalizable by synthetic chemistry methods. Proposed molecular spin qubits include organic radicals, [2] simple coordination complexes, [7] high-spin [1] and low-spin clusters, [3][4][5] and 4f ions.…”

“…[1][2][3][4][5][6] Molecular qubits can be designed such that phase memory times (T m ) approach other solid state electron spin technologies, [7] and have the advantage of being functionalizable by synthetic chemistry methods. Proposed molecular spin qubits include organic radicals, [2] simple coordination complexes, [7] high-spin [1] and low-spin clusters, [3][4][5] and 4f ions. [6] One challenge is to bring together ensembles of such qubits, and particularly to bring together qubits with different electronic g-factors, so called g-engineering, [2,6] which would allow the qubits to be addressed individually and controllably within a complex molecule.…”