scholarly journals Quantum phase interference (Berry phase) in single-molecule magnets of [Mn[sub 12]][sup 2−]

2002 ◽  
Vol 91 (10) ◽  
pp. 7164 ◽  
Author(s):  
W. Wernsdorfer ◽  
M. Soler ◽  
G. Christou ◽  
D. N. Hendrickson
Keyword(s):  
Single Molecule ◽  
Berry Phase ◽  
Quantum Phase ◽  
Single Molecule Magnets ◽  
Phase Interference

Berry-phase blockade and oscillations in single-molecule magnets Mn12 and Fe8 coupled to polarized leads

2019 ◽  
Vol 34 (01) ◽  
pp. 2050005
Author(s):  
Haiyan Yao ◽  
Feng Chi ◽  
Liming Liu
Keyword(s):  
Magnetic Field ◽  
Single Molecule ◽  
Coulomb Blockade ◽  
Berry Phase ◽  
Transverse Magnetic ◽  
Quantum Spin ◽  
Destructive Interference ◽  
Single Molecule Magnets ◽  
Phase Interference ◽  
Coulomb Blockade Regime

We have studied the Berry-phase interference in single-molecule magnets [Formula: see text] and [Formula: see text] coupled to polarized electrodes in the Coulomb blockade regime under external magnetic field. We show that for the oppositely fully polarized leads, the current is completely blockaded as a consequence of the topologically quenched tunnel splitting, which is called as Berry-phase blockade; whereas for the partially polarized leads, the current oscillates periodically with increasing external transverse magnetic field (Berry-phase oscillations). The reason is that different quantum spin tunneling trajectories can combine and give rise to either constructive or destructive interference effects.

Quantum Tunneling and Quantum Phase Interference in a [MnII2MnIII2] Single-Molecule Magnet

2005 ◽  
Vol 127 (32) ◽  
pp. 11311-11317 ◽  
Author(s):  
Lollita Lecren ◽  
Wolfgang Wernsdorfer ◽  
Yang-Guang Li ◽  
Olivier Roubeau ◽  
Hitoshi Miyasaka ◽  
...  
Keyword(s):  
Single Molecule ◽  
Quantum Tunneling ◽  
Quantum Phase ◽  
Single Molecule Magnet ◽  
Phase Interference

scholarly journals Direct spectroscopic observation of Berry-phase interference in the Ni4 single-molecule magnet

2020 ◽  
Vol 102 (22) ◽  
Author(s):  
Brendan C. Sheehan ◽  
Robert Kwark ◽  
Charles A. Collett ◽  
Thomaz A. Costa ◽  
Rafael A. Allão Cassaro ◽  
...  
Keyword(s):  
Single Molecule ◽  
Berry Phase ◽  
Spectroscopic Observation ◽  
Single Molecule Magnet ◽  
Phase Interference

scholarly journals Berry-Phase Blockade in Single-Molecule Magnets

2007 ◽  
Vol 98 (25) ◽  
Author(s):  
Gabriel González ◽  
Michael N. Leuenberger
Keyword(s):  
Single Molecule ◽  
Berry Phase ◽  
Single Molecule Magnets

scholarly journals Asymmetric Berry-Phase Interference Patterns in a Single-Molecule Magnet

2011 ◽  
Vol 106 (22) ◽  
Author(s):  
H. M. Quddusi ◽  
J. Liu ◽  
S. Singh ◽  
K. J. Heroux ◽  
E. del Barco ◽  
...  
Keyword(s):  
Single Molecule ◽  
Berry Phase ◽  
Single Molecule Magnet ◽  
Phase Interference

Seeking Magneto-Structural Correlations in Easily Tailored Pentagonal Bipyramid Dy(III) Single-Ion Magnets

2019 ◽  
Author(s):  
Guo-Zhang Huang ◽  
Ze-Yu Ruan ◽  
Jie-Yu Zheng ◽  
Yan-Cong Chen ◽  
Si-Guo Wu ◽  
...  
Keyword(s):  
Single Molecule ◽  
Structural Engineering ◽  
Magnetic Hysteresis ◽  
Sweep Rate ◽  
Coordination Bond ◽  
Pentagonal Bipyramid ◽  
Single Molecule Magnets ◽  
Crystal Field Theory ◽  
Bond Angles ◽  
Axial Coordination

<p><a></a>Controlling molecular magnetic anisotropy via structural engineering is delicate and fascinating, especially for single-molecule magnets (SMMs). Herein a family of dysprosium single-ion magnets (SIMs) sitting in pentagonal bipyramid geometry have been synthesized with the variable-size terminal ligands and counter anions, through which the subtle coordination geometry of Dy(III) can be finely tuned based on the size effect. The effective energy barrier (Ueff) successfully increases from 439 K to 632 K and the magnetic hysteresis temperature (under a 200 Oe/s sweep rate) raises from 11 K to 24 K. Based on the crystal-field theory, a semi-quantitative magneto-structural correlation deducing experimentally for the first time is revealed that the Ueff is linearly proportional to the structural-related value S2<sup>0</sup> corresponding to the axial coordination bond lengths and the bond angles. Through the evaluation of the remanent magnetization from hysteresis, quantum tunneling of magnetization (QTM) is found to exhibit negative correlation with the structural-related value S<sub>tun</sub> corresponding to the axial coordination bond angles.<br></p>

Correlating Blocking Temperatures in Single Molecule Magnets with Raman Relaxation

2018 ◽  
Author(s):  
Marcus J. Giansiracusa ◽  
Andreas Kostopoulos ◽  
George F. S. Whitehead ◽  
David Collison ◽  
Floriana Tuna ◽  
...  
Keyword(s):  
Relaxation Time ◽  
Single Molecule ◽  
Energy Barrier ◽  
Thermal Relaxation ◽  
Relaxation Mechanism ◽  
Blocking Temperature ◽  
Single Molecule Magnets ◽  
Single Molecule Magnet ◽  
Key Parameter

We report a six coordinate DyIII single-molecule magnet<br>(SMM) with an energy barrier of 1110 K for thermal relaxation of<br>magnetization. The sample shows no retention of magnetization<br>even at 2 K and this led us to find a good correlation between the<br>blocking temperature and the Raman relaxation regime for SMMs.<br>The key parameter is the relaxation time (𝜏<sub>switch</sub>) at the point where<br>the Raman relaxation mechanism becomes more important than<br>Orbach.

A Combined Spin-Flip and IP/EA Approach for Handling Spin and Spatial Degeneracies: Application to Double Exchange Systems

2018 ◽  
Author(s):  
Shannon Houck ◽  
Nicholas Mayhall
Keyword(s):  
Single Molecule ◽  
Double Exchange ◽  
Computational Effort ◽  
Strongly Correlated ◽  
Single Molecule Magnets ◽  
New Approach ◽  
Spin Flip ◽  
Model Hamiltonian ◽  
Simultaneous Existence ◽  
Exchange Parameters

<div>Many multiconfigurational systems, such as single-molecule magnets, are difficult to study using traditional computational methods due to the simultaneous existence of both spin and spatial degeneracies. In this work, a new approach termed n-spin-flip Ionization Potential/Electron Affinity (<i>n</i>SF-IP or <i>n</i>SF-EA) is introduced which combines the spin-flip method of Anna Krylov with particle-number changing IP/EA methods. We demonstrate the efficacy of the approach by applying it to the strongly-correlated N<sub>2</sub><sup>+</sup> as well as several double exchange systems. We also demonstrate that when these systems are well-described by a double exchange model Hamiltonian, only 1SF-IP/EA is required to extract the double exchange parameters and accurately predict energies for the low-spin states. This significantly reduces the computational effort for studying such systems. The effects of including additional excitations (using a RAS-<i>n</i>SF-IP/EA scheme) are also examined, with particular emphasis on hole and particle excitations.</div>

A Combined Spin-Flip and IP/EA Approach for Handling Spin and Spatial Degeneracies: Application to Double Exchange Systems

2018 ◽  
Author(s):  
Shannon Houck ◽  
Nicholas Mayhall
Keyword(s):  
Single Molecule ◽  
Double Exchange ◽  
Computational Effort ◽  
Strongly Correlated ◽  
Single Molecule Magnets ◽  
New Approach ◽  
Spin Flip ◽  
Model Hamiltonian ◽  
Simultaneous Existence ◽  
Exchange Parameters

<div>Many multiconfigurational systems, such as single-molecule magnets, are difficult to study using traditional computational methods due to the simultaneous existence of both spin and spatial degeneracies. In this work, a new approach termed n-spin-flip Ionization Potential/Electron Affinity (<i>n</i>SF-IP or <i>n</i>SF-EA) is introduced which combines the spin-flip method of Anna Krylov with particle-number changing IP/EA methods. We demonstrate the efficacy of the approach by applying it to the strongly-correlated N<sub>2</sub><sup>+</sup> as well as several double exchange systems. We also demonstrate that when these systems are well-described by a double exchange model Hamiltonian, only 1SF-IP/EA is required to extract the double exchange parameters and accurately predict energies for the low-spin states. This significantly reduces the computational effort for studying such systems. The effects of including additional excitations (using a RAS-<i>n</i>SF-IP/EA scheme) are also examined, with particular emphasis on hole and particle excitations.</div>

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