Tight-binding model of Mn<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mrow /><mml:mn>12</mml:mn></mml:msub></mml:math>single-molecule magnets: Electronic and magnetic structure and transport properties

Renani, Fatemeh Rostamzadeh; Kirczenow, George

doi:10.1103/physrevb.85.245415

Cited by 23 publications

(5 citation statements)

References 88 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1 and red bonds in Figs. 8,10), the contribution of this process would be different for J 1 and J 2 . This is explained in details below.…”

Section: A Delocalization Contribution To J1 and J2mentioning

confidence: 99%

“…[3] Challenged by the promising molecular spintronics and quantum computing applications sophisticated SMMs based not only on 3d transition metals but also on the 4d and even on the lanthanide and actinide elements were developed. [4][5][6][7] The theoretical studies have mostly concentrated on the description of the resonant tunneling experiments, [8,9] ab initio simulations, [10][11][12] and investigation of the role of the correlation effects. [13] The single-molecule magnets consist of a core and bridging polynuclear complexes.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Nature of the ferromagnetic ground state in the Mn4molecular magnet

et al. 2014

View full text Add to dashboard Cite

Using ab initio band structure and model calculations we studied magnetic properties of one of the Mn4 molecular magnets (Mn4(hmp)6), where two types of the Mn ions exist: Mn 3+ and Mn 2+ . The direct calculation of the exchange constants in the GGA+U approximation shows that in contrast to a common belief the strongest exchange coupling is not between two Mn 3+ ions (J bb ), but along two out of four exchange paths connecting Mn 3+ and Mn 2+ ions (J wb ). Within the perturbation theory we performed the microscopic analysis of different contributions to the exchange constants, which allows us to establish the mechanism for the largest ferromagnetic exchange. In the presence of the charge order the lowest in energy virtual excitations, contributing to the superexchange, will be not those across the Hubbard gap ∼ U , but will be those between the Mn 3+ and Mn 4+ ions, which cost much smaller energy V (≪ U ). Together with strong Hund's rule coupling and specific orbital order this leads to large ferromagnetic exchange interaction for two out of four Mn 2+ -Mn 3+pairs.

show abstract

“…1 and red bonds in Figs. 8,10), the contribution of this process would be different for J 1 and J 2 . This is explained in details below.…”

Section: A Delocalization Contribution To J1 and J2mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Nature of the ferromagnetic ground state in the Mn4molecular magnet

et al. 2014

View full text Add to dashboard Cite

show abstract

“…Based on computations, a decreased MAE has also been reported for negatively charged Mn 12 O 12 (COOR) 16 (H 2 O) 4 with -H 38 or -C 6 H 5 39 ligands. When a magnetic molecule is adsorbed on a surface, a fractional number of electrons may be transferred to/from the molecule, modifying its MAE.…”

Section: Introductionmentioning

confidence: 79%

Single-Molecule Magnet Mn$_{12}$ on GaAs-supported Graphene: Gate Field Effects From First Principles

Liu,

Yazback,

Fry

et al. 2020

Preprint

View full text Add to dashboard Cite

We study gate field effects on the heterostructure Mn 12 O 12 (COOH) 16 (H 2 O) 4 | graphene | GaAs via first-principles calculations. We find that under moderate doping levels electrons can be added to but not taken from the single-molecule magnet Mn 12 O 12 (COOH) 16 (H 2 O) 4 (Mn 12 ). The magnetic anisotropy energy (MAE) of Mn 12 decreases as the electron doping level increases, due to electron transfer from graphene to Mn 12 and change in the band alignment between Mn 12 and graphene. At an electron doping level of −5.00 × 10 13 cm −2 , the MAE decreases by about 18% compared with zero doping. The band alignment between graphene and GaAs is more sensitive to electron doping than to hole doping, since the valence band of GaAs is close to the Fermi level. The GaAs substrate induces a small band gap in the supported graphene under zero gate field and a nearly strain-free configuration. Finally, we propose a vertical tunnel junction for probing the gate dependence of MAE via electron transport measurements.

show abstract

“…This leads to the important experimental goal of identifying conditions in which the rate of magnetic relaxation of the adsorbed molecule is relatively small. In turn, this encourages the development of new theoretical techniques that yield insights into the physical nature of the magnetic relaxation phenomenon in high-spin molecules [11][12][13][14][15][16]. Experimental techniques such as high-resolution scanning tunnelling microscopy have developed to the point where the spin states of individual molecules adsorbed to a surface can be probed [3,17].…”

Section: Introductionmentioning

confidence: 99%

Stochastic Boltzmann equation for magnetic relaxation in high-spin molecules

2016

View full text Add to dashboard Cite

We introduce the stochastic Boltzmann equation (SBE) as an approach for exploring the spin dynamics of magnetic molecules coupled to a stochastic environment. The SBE is a time-evolution equation for the probability density of the spin density matrix of the system. This probability density is relevant to experiments which take measurements on single molecules, in which probabilities of observing particular spin states (rather than ensemble averages) are of interest. By analogy with standard treatments of the regular Boltzmann equation, we propose a relaxation-time approximation for the SBE, and show that solutions to the SBE under the relaxation-time approximation can be obtained by performing simple trajectory simulations for the case of a boson gas environment.Cases where the relaxation-time approximation are satisfied can therefore be investigated by careful choice of the parameters for the boson gas environment, even if the actual environment is quite different from a boson gas. The application of the SBE approach is demonstrated through an illustrative example.

show abstract

Tight-binding model of Mn12single-molecule magnets: Electronic and magnetic structure and transport properties

Cited by 23 publications

References 88 publications

Nature of the ferromagnetic ground state in the Mn4molecular magnet

Nature of the ferromagnetic ground state in the Mn4molecular magnet

Single-Molecule Magnet Mn$_{12}$ on GaAs-supported Graphene: Gate Field Effects From First Principles

Stochastic Boltzmann equation for magnetic relaxation in high-spin molecules

Contact Info

Product

Resources

About