Spectroscopic Analysis of Vibronic Relaxation Pathways in Molecular Spin Qubit [Ho(W5O18)2]9–: Sparse Spectra Are Key

Using electron spins within molecules for quantum information processing (QIP) was first proposed by Leuenberger and Loss (1), who showed how the Grover algorithm could be mapped onto a Mn12 cage (2). Since then several groups have examined two-level (S = ½) molecular spin systems as possible qubits (3-12). There has also been a report of the implementation of the Grover algorithm in a four-level molecular qudit (13). A major challenge is to protect the spin qubit from noise that causes loss of phase information; strategies to minimize the impact of noise on qubits can be categorized as corrective, reductive, or protective. Corrective approaches allow noise and correct for its impact on the qubit using advanced microwave pulse sequences (3). Reductive approaches reduce the noise by minimising the number of nearby nuclear spins (7-11), and increasing the rigidity of molecules to minimise the effect of vibrations (which can cause a fluctuating magnetic field via spin-orbit coupling) (9,11); this is essentially engineering the ligand shell surrounding the electron spin. A protective approach would seek to make the qubit less sensitive to noise: an example of the protective approach is the use of clock transitions to render spin states immune to magnetic fields at first order (12). Here we present a further protective method that would complement reductive and corrective approaches to enhancing quantum coherence in molecular qubits. The target is a molecular spin qubit with an effective 2S ground state: we achieve this with a family of divalent rare-earth molecules that have negligible magnetic anisotropy such that the isotropic nature of the electron spin renders the qubit markedly less sensitive to magnetic noise, allowing coherent spin manipulations even at room temperature. If combined with the other strategies, we believe this could lead to molecular qubits with substantial advantages over competing qubit proposals.<br>

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Molecular spin qudits for quantum algorithms

Chemical Society Reviews ◽

10.1039/c5cs00933b ◽

2018 ◽

Vol 47 (2) ◽

pp. 501-513 ◽

Cited By ~ 87

Author(s):

Eufemio Moreno-Pineda ◽

Clément Godfrin ◽

Franck Balestro ◽

Wolfgang Wernsdorfer ◽

Mario Ruben

Keyword(s):

Quantum Information ◽

First Generation ◽

Quantum Information Processing ◽

Quantum Algorithms ◽

Quantum Algorithm ◽

Building Blocks ◽

Molecular Devices ◽

Hardware Platform ◽

Spin Qubit ◽

Molecular Spin

Molecules are promising building blocks for Quantum information processing. Herein we describe how a molecular multilevel nuclear spin qubit (or qudit, where d = 4), known as TbPc2, showing all necessary requirements to perform as a molecular hardware platform with a first generation of molecular devices enabling even quantum algorithm operations.

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Structural Determination of a DNA Oligomer for a Molecular Spin Qubit Lloyd Model of Quantum Computers

Zeitschrift für Physikalische Chemie ◽

10.1515/zpch-2016-0799 ◽

2017 ◽

Vol 231 (2) ◽

Cited By ~ 1

Author(s):

Satoru Yamamoto ◽

Shigeaki Nakazawa ◽

Kenji Sugisaki ◽

Kensuke Maekawa ◽

Kazunobu Sato ◽

...

Keyword(s):

Electron Spin ◽

Quantum Information Processing ◽

Double Resonance ◽

Structural Determination ◽

Dna Duplex ◽

Periodic Arrays ◽

Spin Qubit ◽

Molecular Spin ◽

Equivalent Electron

AbstractThe global molecular and local spin-site structures of a DNA duplex 22-oligomer with site-directed four spin-labeling were simulated by molecular mechanics (MM) calculations combined with Q-band pulsed electron-electron double resonance (PELDOR) spectroscopy. This molecular-spin bearing DNA oligomer is designed to give a complex testing ground for the structural determination of molecular spins incorporated in the DNA duplex, which serves as a platform for 1D periodic arrays of two or three non-equivalent electron spin qubit systems, (AB)n or (ABC)n, respectively, enabling to execute quantum computing or quantum information processing (Lloyd model of electron spin versions): A, B and C designate non-equivalent addressable spin qubits for quantum operations. The non-equivalence originates in difference in the electronic

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Molecular-Spin-Qubit Noise Spectroscopy Through Dynamical Decoupling

Physical Review Applied ◽

10.1103/physrevapplied.15.l061001 ◽

2021 ◽

Vol 15 (6) ◽

Author(s):

Yue Fu ◽

Yang Wu ◽

Yingqiu Dai ◽

Xi Qin ◽

Xing Rong ◽

...

Keyword(s):

Dynamical Decoupling ◽

Noise Spectroscopy ◽

Spin Qubit ◽

Molecular Spin

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Engineering Electronic Structure to Protect Phase Memory in Molecular Qubits by Minimising Orbital Angular Momentum

10.26434/chemrxiv.7067645 ◽

2018 ◽

Author(s):

Ana Maria Ariciu ◽

David H. Woen ◽

Daniel N. Huh ◽

Lydia Nodaraki ◽

Andreas Kostopoulos ◽

...

Keyword(s):

Electron Spin ◽

Quantum Coherence ◽

Quantum Information Processing ◽

Pulse Sequences ◽

Grover Algorithm ◽

Ligand Shell ◽

Information Strategies ◽

Spin Qubit ◽

Molecular Spin ◽

The Impact

Using electron spins within molecules for quantum information processing (QIP) was first proposed by Leuenberger and Loss (1), who showed how the Grover algorithm could be mapped onto a Mn12 cage (2). Since then several groups have examined two-level (S = ½) molecular spin systems as possible qubits (3-12). There has also been a report of the implementation of the Grover algorithm in a four-level molecular qudit (13). A major challenge is to protect the spin qubit from noise that causes loss of phase information; strategies to minimize the impact of noise on qubits can be categorized as corrective, reductive, or protective. Corrective approaches allow noise and correct for its impact on the qubit using advanced microwave pulse sequences (3). Reductive approaches reduce the noise by minimising the number of nearby nuclear spins (7-11), and increasing the rigidity of molecules to minimise the effect of vibrations (which can cause a fluctuating magnetic field via spin-orbit coupling) (9,11); this is essentially engineering the ligand shell surrounding the electron spin. A protective approach would seek to make the qubit less sensitive to noise: an example of the protective approach is the use of clock transitions to render spin states immune to magnetic fields at first order (12). Here we present a further protective method that would complement reductive and corrective approaches to enhancing quantum coherence in molecular qubits. The target is a molecular spin qubit with an effective 2S ground state: we achieve this with a family of divalent rare-earth molecules that have negligible magnetic anisotropy such that the isotropic nature of the electron spin renders the qubit markedly less sensitive to magnetic noise, allowing coherent spin manipulations even at room temperature. If combined with the other strategies, we believe this could lead to molecular qubits with substantial advantages over competing qubit proposals.<br>

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Polyanisotropic Magnetoelectric Coupling in an Electrically Controlled Molecular Spin Qubit

Journal of the American Chemical Society ◽

10.1021/jacs.9b09101 ◽

2019 ◽

Vol 141 (50) ◽

pp. 19765-19775 ◽

Cited By ~ 2

Author(s):

Jérôme Robert ◽

Nathalie Parizel ◽

Philippe Turek ◽

Athanassios K. Boudalis

Keyword(s):

Magnetoelectric Coupling ◽

Spin Qubit ◽

Molecular Spin

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Molecular Optimization for Nuclear Spin State Control via a Single Electron Spin Qubit by Optimal Microwave Pulses: Quantum Control of Molecular Spin Qubits

Applied Magnetic Resonance ◽

10.1007/s00723-021-01392-5 ◽

2021 ◽

Author(s):

Taiki Shibata ◽

Satoru Yamamoto ◽

Shigeaki Nakazawa ◽

Elham Hosseini Lapasar ◽

Kenji Sugisaki ◽

...

Keyword(s):

Electron Spin ◽

Spin State ◽

Nuclear Spin ◽

Quantum Control ◽

Single Electron ◽

State Control ◽

Spin Qubits ◽

Microwave Pulses ◽

Spin Qubit ◽

Molecular Spin

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Characterization of Chemical Impurities in Glutaraldehyde

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100116723 ◽

1975 ◽

Vol 33 ◽

pp. 620-621

Author(s):

B. J. Grenon ◽

A. J. Tousimis

Keyword(s):

Glutaric Acid ◽

Spectroscopic Analysis ◽

Aldol Condensation ◽

Condensation Product ◽

Amorphous Solid ◽

Water Soluble ◽

Impurity Component ◽

Chemical Impurities ◽

Soluble Liquid

Ever since the introduction of glutaraldehyde as a fixative in electron microscopy of biological specimens, the identification of impurities and consequently their effects on biologic ultrastructure have been under investigation. Several reports postulate that the impurities of glutaraldehyde, used as a fixative, are glutaric acid, glutaraldehyde polymer, acrolein and glutaraldoxime.Analysis of commercially available biological or technical grade glutaraldehyde revealed two major impurity components, none of which has been reported. The first compound is a colorless, water-soluble liquid with a boiling point of 42°C at 16 mm. Utilizing Nuclear Magnetic Resonance (NMR) spectroscopic analysis, this compound has been identified to be — dihydro-2-ethoxy 2H-pyran. This impurity component of the glutaraldehyde biological or technical grades has an UV absorption peak at 235nm. The second compound is a white amorphous solid which is insoluble in water and has a melting point of 80-82°C. Initial chemical analysis indicates that this compound is an aldol condensation product(s) of glutaraldehyde.

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Elemental analysis of human erythrocytes

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010015318x ◽

1989 ◽

Vol 47 ◽

pp. 242-243

Author(s):

S. A. Livesey ◽

A. A. del Campo ◽

E. S. Griffey ◽

D. Ohlmer ◽

T. Schifani ◽

...

Keyword(s):

Sample Preparation ◽

Elemental Analysis ◽

Human Erythrocyte ◽

Spectroscopic Analysis ◽

Model System ◽

Human Erythrocytes ◽

List Type ◽

Chemical Fixation ◽

Ethanol Dehydration ◽

Lowicryl K4m

The aim of this study is to compare methods of sample preparation for elemental analysis. The model system which is used is the human erythrocyte. Energy dispersive spectroscopic analysis has been previously reported for cryofixed and cryosectioned erythrocytes. Such work represents the reference point for this study. The use of plastic embedded samples for elemental analysis has also been documented. The work which is presented here is based on human erythrocytes which have been either chemically fixed and embedded or cryofixed and subsequently processed by a variety of techniques which culminated in plastic embedded samples.Heparinized and washed erythrocytes were prepared by the following methods for this study :(1). Chemical fixation in 4% paraformaldehyde/0.25% glutaraldehyde/0.2 M sucrose in 0.1 M Na cacodylate, pH 7.3 for 30 min, followed by ethanol dehydration, infiltration and embedding in Lowicryl K4M at -20° C.

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