Showing papers on "Spin states published in 2006"
TL;DR: In the lanthanide-containing phthalocyanine complexes reported in the literature the ligand environment induces a large splitting of the ground Jmanifold, whereas in SMMs large-spin ground states arising from magnetic interactions between the metal centers of the cluster can enhance the weaker single-ion.
Abstract: The study of paramagnetic metal-ion aggregates has been of increasing interest since the observation that such molecules can exhibit magnetic memory effects. Termed singlemolecule magnets or SMMs, the important factors leading to such properties derive from the combination of a large ground-state spin and a large magnetic anisotropy of the Ising (easy-axis) type. Studies have largely been based on transition-metal compounds since they typically exhibit both of the aforementioned features. The incorporation of lanthanides into these complexes has been investigated to take advantage of the potentially large number of unpaired f-electrons available. However, very little work has been done to date on purely lanthanide-based systems. The origin of SMM behavior in lanthanide-containing compounds is more complicated than that of d-block transition-metal ions since there is likely to be a significant orbital component. In the lanthanide-containing phthalocyanine complexes reported in the literature the ligand environment induces a large splitting of the ground Jmanifold, whereas in SMMs large-spin ground states arising from magnetic interactions between the metal centers of the cluster can enhance the weaker single-ion
770 citations
TL;DR: In this article, an artificial geometrically frustrated magnet based on an array of lithographically fabricated single-domain ferromagnetic islands is presented, where the islands are arranged such that the dipole interactions create a two-dimensional analogue to spin ice.
Abstract: When a number of interactions compete within a system they can't all prevail, so the resolution of ‘frustrated’ forces is an important determinant of the overall behaviour of a system. In particular, geometrical frustration among spins in magnetic systems can lead to exotic effects such as ‘spin ice’, a state where atomic magnetic moments mimic the frustration of hydrogen ion positions in water ice. Wang et al. have created artificial spin ice using lithographically fabricated arrays of nanoscale magnets. Magnetic moments in the lattice follow the two [pointing]-in/ two-out ‘ice rule’ typical of spin ice. With this model it is possible to study frustration in great detail; this is relevant to magnetic recording, where ferromagnetic elements are being pushed to ever higher densities. On the cover, a magnetic force microscopy representation of the magnetization pattern of artificial spin ice: plateaus and valleys show regions of opposite magnetization. Frustration, defined as a competition between interactions such that not all of them can be satisfied, is important in systems ranging from neural networks to structural glasses. Geometrical frustration, which arises from the topology of a well-ordered structure rather than from disorder, has recently become a topic of considerable interest1. In particular, geometrical frustration among spins in magnetic materials can lead to exotic low-temperature states2, including ‘spin ice’, in which the local moments mimic the frustration of hydrogen ion positions in frozen water3,4,5,6. Here we report an artificial geometrically frustrated magnet based on an array of lithographically fabricated single-domain ferromagnetic islands. The islands are arranged such that the dipole interactions create a two-dimensional analogue to spin ice. Images of the magnetic moments of individual elements in this correlated system allow us to study the local accommodation of frustration. We see both ice-like short-range correlations and an absence of long-range correlations, behaviour which is strikingly similar to the low-temperature state of spin ice. These results demonstrate that artificial frustrated magnets can provide an uncharted arena in which the physics of frustration can be directly visualized.
662 citations
539 citations
TL;DR: Laser cooling of a single electron spin trapped in a semiconductor quantum dot is demonstrated, which corresponds to a spin-state preparation with a fidelity exceeding 99.8% within the framework of quantum information processing.
Abstract: We have demonstrated laser cooling of a single electron spin trapped in a semiconductor quantum dot. Optical coupling of electronic spin states was achieved using resonant excitation of the charged quantum dot (trion) transitions along with the heavy-light hole mixing, which leads to weak yet finite rates for spin-flip Raman scattering. With this mechanism, the electron spin can be cooled from 4.2 to 0.020 kelvin, as confirmed by the strength of the induced Pauli blockade of the trion absorption. Within the framework of quantum information processing, this corresponds to a spin-state preparation with a fidelity exceeding 99.8%.
498 citations
TL;DR: Using soft x-ray absorption spectroscopy and magnetic circular dichroism at the Co$L 2,3 ) edge, the spin state transition in LaCoO$3}$ can be well described by a low-spin ground state and a triply-degenerate high-spin first excited state.
Abstract: Using soft x-ray absorption spectroscopy and magnetic circular dichroism at the Co-$L_{2,3}$ edge we reveal that the spin state transition in LaCoO$_{3}$ can be well described by a low-spin ground state and a triply-degenerate high-spin first excited state. From the temperature dependence of the spectral lineshapes we find that LaCoO$_{3}$ at finite temperatures is an inhomogeneous mixed-spin-state system. Crucial is that the magnetic circular dichroism signal in the paramagnetic state carries a large orbital momentum. This directly shows that the currently accepted low-/intermediate-spin picture is at variance. Parameters derived from these spectroscopies fully explain existing magnetic susceptibility, electron spin resonance and inelastic neutron data.
339 citations
TL;DR: In this paper, a model for anomalous magnetoresistance and its change with doping based on the charge transport in these semiconductors being electron-hole recombination limited was proposed.
294 citations
TL;DR: X-ray emission spectra of Fe(III), Fe(II), and Co(II) spin-crossover compounds in their high-spin and low-spin forms are reported and it is shown that all X-Ray emission features are sensitive to the spin state.
Abstract: We report X-ray emission spectra of Fe, Fe, and Cospin-crossover compounds in their high-spin and low-spin forms. It is shown that all X-ray emission features are sensitive to the spin state. Variations of the K
250 citations
TL;DR: An atom-by-atom substitution technique using a scanning tunnelling microscope is described and applied to perform a controlled study at the atomic scale of the interactions between isolated Mn acceptors, which are mediated by holes in GaAs to reveal a strong dependence of ferromagnetic interaction on crystallographic orientation.
Abstract: The addition of metals as 'dopants to semiconductors is used to adjust the electronic properties of transistors and diodes. A new study uses atomically precise substitution of individual dopants to measure their interactions on the nanometre scale. The discovery of ferromagnetism in manganese-doped gallium arsenide sparked interest in semiconductors based on electron spin, or spintronics. This study uses scanning tunnelling microscopy to visualize the GaAs electronic states involved in Mn–Mn interactions. A strong dependence of ferromagnetic interaction on crystal orientation is seen, a property that might be exploited by growing oriented structures with ferromagnetic transition temperatures beyond those of randomly doped samples. This could also lead to coupled quantum bits for memory or information processing. Cover graphic: Mn hole states visualized on a GaAs surface mediate magnetic interactions between spin states. The discovery of ferromagnetism in Mn-doped GaAs1 has ignited interest in the development of semiconductor technologies based on electron spin and has led to several proof-of-concept spintronic devices2,3,4. A major hurdle for realistic applications of Ga1-xMnxAs, or other dilute magnetic semiconductors, remains that their ferromagnetic transition temperature is below room temperature. Enhancing ferromagnetism in semiconductors requires us to understand the mechanisms for interaction between magnetic dopants, such as Mn, and identify the circumstances in which ferromagnetic interactions are maximized5. Here we describe an atom-by-atom substitution technique using a scanning tunnelling microscope (STM) and apply it to perform a controlled study at the atomic scale of the interactions between isolated Mn acceptors, which are mediated by holes in GaAs. High-resolution STM measurements are used to visualize the GaAs electronic states that participate in the Mn–Mn interaction and to quantify the interaction strengths as a function of relative position and orientation. Our experimental findings, which can be explained using tight-binding model calculations, reveal a strong dependence of ferromagnetic interaction on crystallographic orientation. This anisotropic interaction can potentially be exploited by growing oriented Ga1-xMnxAs structures to enhance the ferromagnetic transition temperature beyond that achieved in randomly doped samples.
218 citations
TL;DR: It is concluded that La4Ru2O10 appears to be a novel material in which the orbital physics drives the formation of spin-singlet dimers in a quasi-two-dimensional S=1 system.
Abstract: Using x-ray absorption spectroscopy at the Ru-L2;3 edge we reveal that the Ru 4� ions remain in the S � 1 spin state across the rare 4d-orbital ordering transition and spin-gap formation. We find using local spin density approximationHubbard U band structure calculations that the crystal fields in the low- temperature phase are not strong enough to stabilize the S � 0 state. Instead, we identify a distinct orbital ordering with a significant anisotropy of the antiferromagnetic exchange couplings. We conclude that La4Ru2O10 appears to be a novel material in which the orbital physics drives the formation of spin-singlet dimers in a quasi-two-dimensional S � 1 system.
214 citations
TL;DR: The principal conclusion is that the degree of deuteration of molecular ions and molecules is sensitive to the ortho:para H 2 ratio and hence to the chemical and thermal history of the precursor molecular cloud.
Abstract: Context. We have studied the evolution of molecular gas during the early stages of protostellar collapse, when the freeze-out of "heavy" species on to grains occurs. Aims. In addition to studying the freeze-out of "heavy" species on to grains, we wished to compute the variation of the population densities of the different nuclear spin states of 'tracer' molecular ions, such as H 2 D + and D 2 H + , which are currently observed only in their ortho and para forms, respectively. Methods. Chemical processes which determine the relative populations of the nuclear spin states of molecules and molecular ions were included explicitly. Nuclear spin-changing reactions have received much less attention in the literature than those leading to deuteration; but, in fact, the former processes are as significant as the latter and often involve the same reactants. A "free-fall" model of gravitational collapse was adopted. Results. We found that the ortho:para ratios of some species, e.g. H 2 D + , vary considerably as the density increases. Because the dynamical timescale is much shorter than some of the chemical timescales, there can be large departures of the predictions of the free-fall model from the steady-state solution at the same density and temperature. In the case of H 2 , it seems unlikely that the steady state value of the ortho:para ratio is attained before protostellar collapse from the progenitor molecular cloud commences. Values of the ortho:para H 2 ratio much higher than in steady state, which would prevail in "young" molecular clouds, are found to be inconsistent with high levels of deuteration of the gas. The internal energy of ortho-H 2 acts as a reservoir of chemical energy which inhibits the deuteration of H + 3 and hence of other species, such as N 2 H + and NH 3 . Conclusions. The principal conclusion is that the degree of deuteration of molecular ions and molecules is sensitive to the ortho:para H 2 ratio and hence to the chemical and thermal history of the precursor molecular cloud.
203 citations
TL;DR: This work interprets an excitation in LaCoO3 as originating from a transition between thermally excited states located about 120 K above the ground state, and discusses the nature of the magnetic excited state in terms of intermediate-spin versus high-spin states.
Abstract: A gradual spin-state transition occurs in LaCoO3 around T ∼ 80 −120 K, whose detailed nature remains controversial. We studied this transition by means of inelastic neutron scattering (INS), and found that with increasing temperature an excitation at ∼ 0.6 meV appears, whose intensity increases with temperature, following the bulk magnetization. Within a model including crystal field interaction and spin-orbit coupling we interpret this excitation as originating from a transition between thermally excited states located about 120 K above the ground state. We further discuss the nature of the magnetic excited state in terms of intermediate-spin (IS, t 5g e 1 , S = 1) vs. highspin (HS, t 4g e 2, S = 2) states. Since the g-factor obtained from the field dependence of the INS is g ∼ 3, the second interpretation looks more plausible.
TL;DR: In this paper, the authors proposed a nonadiabatic multi-phonon process in the strong coupling limit, in which the low-temperature tunnelling rate increases exponentially with the zero point energy difference between the two states.
TL;DR: In this article, the authors review progress over the past several years concerning the rare earth titanates, R 2 Ti 2 O 7, which show a remarkable sensitivity to the electronic structure, specifically, the crystal field ground state of the R 3+ ion.
TL;DR: Several cases are identified, involving Fe(III) porphyrins and related systems, where common functionals fail to correctly describe the energetics of the different low-lying spin states.
Abstract: Although density functional theory (DFT) provides a generally good description of transition metal systems, we have identified several cases, involving Fe(III) porphyrins and related systems, where common functionals fail to correctly describe the energetics of the different low-lying spin states. The question of metal- versus ligand-centered oxidation in high-valent transition metal complexes is also a challenging one for DFT calculations, as I have tried to illustrate with examples from among porphyrin, corrole, biliverdine, and NO complexes. In a number of cases, I have compared results obtained with different exchange–correlation functionals; in addition, I have added a discussion on the relative performance of pure versus hybrid functionals. Finally, I have offered some thoughts on the role that traditional wavefunction-based ab initio methods, now essentially absent from the bioinorganic arena, might play in the future.
TL;DR: The presence of dynamical chiral order parameter domains of the form px ± ipy in the ruthenate superconductor Sr2 RuO4 confirms the p-wave triplet spin and complex (broken time-reversal symmetry) nature of the superconducting pairing state in Sr2RuO4.
Abstract: We present direct evidence for complex p-wave order parameter symmetry and the presence of dynamical chiral order parameter domains of the form px +/- ipy in the ruthenate superconductor Sr2RuO4. The domain structure creates differences in the magnetic field modulation of the critical current of Josephson junctions fabricated on orthogonal faces of Sr2RuO4 single crystals. Transitions between the chiral states of a domain or the motion of domain walls separating them generates telegraph noise in the critical current as a function of magnetic field or time and is responsible for hysteresis observed in field sweeps of the critical current. The presence of such domains confirms the p-wave triplet spin and complex (broken time-reversal symmetry) nature of the superconducting pairing state in Sr2RuO4.
TL;DR: In this paper, an S = 1 spin model on a triangular lattice with bilinear-biquadratic interactions was investigated for an antiferro nematic order phase with a three-sublattice structure, and magnetic properties at zero temperature by bosonization.
Abstract: Spin nematic order is investigated for an S =1 spin model on a triangular lattice with bilinear–biquadratic interactions. We particularly studied an antiferro nematic order phase with a three-sublattice structure, and magnetic properties are calculated at zero temperature by bosonization. Two types of bosonic excitations are found and we calculated dynamic and static spin correlations. One is a gapless excitation with linear energy dispersion around k ∼ 0 , and this leads to a finite spin susceptibility at T =0 and would have a specific heat C ( T ) ∼ T 2 at low temperatures. These behaviors can explain many of the characteristic features of a recently discovered spin liquid state in the triangular magnet, NiGa 2 S 4 .
TL;DR: In this article, the coherence in the collisionally driven spin-dynamics of ultracold atom pairs trapped in optical lattices was used to determine the spin-dependent interaction strength in the interaction Hamiltonian.
Abstract: We report on precision measurements of spin-dependent interaction-strengths in the 87Rb spin-1 and spin-2 hyperfine ground states. Our method is based on the recent observation of coherence in the collisionally driven spin-dynamics of ultracold atom pairs trapped in optical lattices. Analysis of the Rabi-type oscillations between two spin states of an atom pair allows a direct determination of the coupling parameters in the interaction Hamiltonian. We deduce differences in scattering lengths from our data that can directly be compared to theoretical predictions in order to test interatomic potentials. Our measurements agree with the predictions within 20%. The knowledge of these coupling parameters allows one to determine the nature of the magnetic ground state. Our data imply a ferromagnetic ground state for 87Rb in the f = 1 manifold, in agreement with earlier experiments performed without the optical lattice. For 87Rb in the f = 2 manifold, the data point towards an antiferromagnetic ground state; however our error bars do not exclude a possible cyclic phase.
TL;DR: The application of generalized polyhedral interconversion coordinates to the study of the potential energy surfaces that define the stereochemical choice in four-coordinate transition metal complexes with different spin states is presented, and the correlation between potential energy curves and distribution of experimental structures along the tetrahedron to square interconverted path is shown.
Abstract: Generalized polyhedral interconversion coordinates are defined within the framework of Avnir's continuous shape measures. The application of such interconversion coordinates to the study of the potential energy surfaces that define the stereochemical choice in four-coordinate transition metal complexes with different spin states is presented, and the correlation between potential energy curves and distribution of experimental structures along the tetrahedron to square interconversion path is shown for the case of the d6 transition-metal complexes.
TL;DR: In this paper, the spin moment of cobalt was studied at room temperature and pressure-induced spin transitions with the emission spectra of LaCoO 3, and it was shown that the material becomes low spin between 40 and 70 kbar at high pressure, and the first thermal transition is best described by a transition to an orbitally nondegenerate intermediate spin state.
Abstract: We report the continuous variation of the spin moment of cobalt in ${\mathrm{LaCoO}}_{3}$ across its temperature and pressure-induced spin transitions evidenced with $K\ensuremath{\beta}$ emission spectra. The first thermal transition is best described by a transition to an orbitally nondegenerate intermediate spin $(S=1)$ state. In parallel, continuous redistribution of the $3d$ electrons is also indicated by partial fluorescence yield x-ray absorption spectra. At high pressure, our study confirms that the material becomes low spin between 40 and 70 kbar at room temperature.
TL;DR: In this paper, the authors investigated theoretically electron spin states in one-dimensional and two-dimensional (2D) hard-wall mesoscopic rings in the presence of both the Rashba spin-orbit interaction (RSOI) and the Dresselhaus spinorbit interaction in a perpendicular magnetic field.
Abstract: We investigate theoretically electron spin states in one-dimensional and two-dimensional (2D) hard-wall mesoscopic rings in the presence of both the Rashba spin-orbit interaction (RSOI) and the Dresselhaus spin-orbit interaction (DSOI) in a perpendicular magnetic field. The Hamiltonian of the RSOI alone is mathematically equivalent to that of the DSOI alone using an SU(2) spin rotation transformation. Our theoretical results show that the interplay between the RSOI and DSOI results in an effective periodic potential, which consequently leads to gaps in the energy spectrum. This periodic potential also weakens and smoothens the oscillations of the persistent charge current and spin current and results in the localization of electrons. For a 2D ring with a finite width, higher radial modes destroy the periodic oscillations of persistent currents.
TL;DR: In this paper, the authors present a first step in the search for polynuclear spin crossover molecules of nanometric dimensions, which could be used as multi-stepped molecular switches.
Abstract: Dinuclear spin crossover molecules can adopt three different spin-pair states: a fully diamagnetic low spin state, [LS–LS], with both iron(II) atoms in the LS state; a paramagnetic mixed spin-pair state [LS–HS]; and an antiferromagnetically coupled [HS–HS] state. Stabilisation of the [LS–HS] state depends on a subtle balance between intra- and inter-molecular interactions in the solid state, consequently, the thermal dependence of the physical and structural properties can present one-step or two-step spin transitions. The former case involves the [LS–LS] ↔ [HS–HS] transformation while in the latter case the intermediate stage responsible for the plateau, at 50% conversion between the two steps, is observed. It may be due to the formation of a 50% mixture of [HS–HS] and [LS–LS] or to the existence of 100% [LS–HS] species. In some cases switching between the three spin-pair states has been observed upon the action of temperature, pressure or light, which implies competition between magnetic coupling and spin crossover phenomena. The results here reviewed represent a first step in the search for polynuclear spin crossover molecules of nanometric dimensions, which could be used as multi-stepped molecular switches.
TL;DR: The results reveal similarities as well as some pronounced differences in the properties of the molecule in the two alternative spin states using density functional (DFT) and simplified correlated multireference ab initio methods.
TL;DR: The device permits us to prepare the dot in states with three different electric charges, 0, +1e, and -1e which result in dramatically different spin properties, as revealed by photoluminescence.
Abstract: We report on the reversible electrical control of the magnetic properties of a single Mn atom in an individual quantum dot. Our device permits us to prepare the dot in states with three different electric charges, 0, $+1e$, and $\ensuremath{-}1e$ which result in dramatically different spin properties, as revealed by photoluminescence. Whereas in the neutral configuration the quantum dot is paramagnetic, the electron-doped dot spin states are spin rotationally invariant and the hole-doped dot spins states are quantized along the growth direction.
TL;DR: In this article, the authors theoretically investigate inelastic transport through anisotropic magnetic molecules weakly coupled to one ferromagnetic and one nonmagnetic lead, and they find that the current is suppressed over wide voltage ranges due to spin blockade.
Abstract: We theoretically investigate inelastic transport through anisotropic magnetic molecules weakly coupled to one ferromagnetic and one nonmagnetic lead. We find that the current is suppressed over wide voltage ranges due to spin blockade. In this system, spin blockade is associated with successive spin flips of the molecular spin and depends on the anisotropy energy barrier. This leads to the appearance of a window of bias voltages between the Coulomb blockade and spin blockade regimes where the current is large and to negative differential conductance. Remarkably, negative differential conductance is also present close to room temperature. Spin-blockade behavior is accompanied by super-Poissonian shot noise, such as in nonmagnetic quantum dots. Finally, we show that the charge transmitted through the molecule between initial preparation in a certain spin state and infinite time strongly depends on the initial spin state in certain parameter ranges. Thus the molecule can act as a spin-charge converter, an effect potentially useful as a read-out mechanism for molecular spintronics.
TL;DR: In this paper, the authors reported precision measurements of spin-dependent interaction-strengths in the 87Rb spin-1 and spin-2 hyperfine ground states, based on the recent observation of coherence in the collisionally driven spin-dynamics of ultracold atom pairs trapped in optical lattices.
Abstract: We report on precision measurements of spin-dependent interaction-strengths in the 87Rb spin-1 and spin-2 hyperfine ground states. Our method is based on the recent observation of coherence in the collisionally driven spin-dynamics of ultracold atom pairs trapped in optical lattices. Analysis of the Rabi-type oscillations between two spin states of an atom pair allows a direct determination of the coupling parameters in the interaction hamiltonian. We deduce differences in scattering lengths from our data that can directly be compared to theoretical predictions in order to test interatomic potentials. Our measurements agree with the predictions within 20%. The knowledge of these coupling parameters allows one to determine the nature of the magnetic ground state. Our data imply a ferromagnetic ground state for 87Rb in the f=1 manifold, in agreement with earlier experiments performed without the optical lattice. For 87Rb in the f=2 manifold the data points towards an antiferromagnetic ground state, however our error bars do not exclude a possible cyclic phase.
TL;DR: It is conjecture that this DFT+U approach may be a useful general method for modeling first-row transition metal ion complexes in a condensed-matter setting.
Abstract: We apply density functional theory (DFT) and the DFT+U technique to study the adsorption of transition metal porphine molecules on atomistically flat Au(111) surfaces. DFT calculations using the Perdew-Burke-Ernzerhof exchange correlation functional correctly predict the palladium porphine (PdP) low-spin ground state. PdP is found to adsorb preferentially on gold in a flat geometry, not in an edgewise geometry, in qualitative agreement with experiments on substituted porphyrins. It exhibits no covalent bonding to Au(111), and the binding energy is a small fraction of an electronvolt. The DFT+U technique, parametrized to B3LYP-predicted spin state ordering of the Mn d-electrons, is found to be crucial for reproducing the correct magnetic moment and geometry of the isolated manganese porphine (MnP) molecule. Adsorption of Mn(II)P on Au(111) substantially alters the Mn ion spin state. Its interaction with the gold substrate is stronger and more site-specific than that of PdP. The binding can be partially reversed by applying an electric potential, which leads to significant changes in the electronic and magnetic properties of adsorbed MnP and approximately 0.1 A changes in the Mn-nitrogen distances within the porphine macrocycle. We conjecture that this DFT+U approach may be a useful general method for modeling first-row transition metal ion complexes in a condensed-matter setting.
TL;DR: Interestingly, the solvent can be re-introduced into the monosolvated solid to achieve complete conversion back to the original two-step crossover material, [Fe(2)(ddpp)(2)(NCS)(4)]4 CH(2)Cl(2).
Abstract: A dinuclear iron(II) complex containing the new pyridyl bridging ligand, 2,5-di(2′,2′′-dipyridylamino)pyridine (ddpp) has been synthesised and characterised by single-crystal X-ray diffraction, magnetic susceptibility and Mossbauer spectral methods. This compound, [Fe2(ddpp)2(NCS)4]⋅4 CH2Cl2, undergoes a two-step full spin crossover. Structural analysis at each of the three plateau temperatures has revealed a dinuclear molecule with spin states HS–HS, HS–LS and LS–LS (HS: high spin, LS: low spin) for the two iron(II) centres. This is the first time that resolution of the metal centres in a HS–LS ordered state has been achieved in a two-step dinuclear iron(II) spin-crossover compound. Thermogravimetric data show that the dichloromethane solvate molecules can be removed in two distinct steps at 120 °C and 200 °C. The partially de-solvated clathrate, [Fe2(ddpp)2(NCS)4]⋅CH2Cl2, undergoes a one-step transition with an increased transition temperature with respect to the as synthesised material. Structural characterisation of this material reveals subtle changes to the coordination geometries at each of the iron(II) centres and striking changes to the local environment of the dinuclear complex. The fully de-solvated material remains high spin over all temperatures. Interestingly, the solvent can be re-introduced into the monosolvated solid to achieve complete conversion back to the original two-step crossover material, [Fe2(ddpp)2(NCS)4]⋅4 CH2Cl2.
TL;DR: A phenomenological model for the change in g factor based on resonant changes in the amplitude of the wave function in the barrier due to the formation of bonding and antibonding orbitals is proposed.
Abstract: We present a magnetophotoluminescence study of individual vertically stacked $\mathrm{InAs}/\mathrm{GaAs}$ quantum dot pairs separated by thin tunnel barriers. As an applied electric field tunes the relative energies of the two dots, we observe a strong resonant increase or decrease in the $g$ factors of different spin states that have molecular wave functions distributed over both quantum dots. We propose a phenomenological model for the change in $g$ factor based on resonant changes in the amplitude of the wave function in the barrier due to the formation of bonding and antibonding orbitals.
TL;DR: The structures, electron configurations, magnetic susceptibilities, spectroscopic properties, molecular orbital energies and spin density distributions, redox properties and reactivities of iron corrolates having chloride, phenyl, pyridine, NO and other ligands are reviewed.
TL;DR: The crystal structure and magnetic properties of FeTe2O5X (X = Cl, Br) as mentioned in this paper, a frustrated spin cluster compound with a new Te(IV) coordination polyhedron.
Abstract: Crystal structure and magnetic properties of FeTe2O5X (X = Cl, Br) – a frustrated spin cluster compound with a new Te(IV) coordination polyhedron