Theoretical study of strain-dependent optical absorption in a doped self-assembled InAs/InGaAs/GaAs/AlGaAs quantum dot

• Tarek A. Ameen,
• Hesameddin Ilatikhameneh,
• Archana Tankasala,
• Yuling Hsueh,
• James Charles,
• Jim Fonseca,
• Michael Povolotskyi,
• Jun Oh Kim,
• Sanjay Krishna,
• Monica S. Allen,
• Jeffery W. Allen,
• Rajib Rahman and
• Gerhard Klimeck

Beilstein J. Nanotechnol. 2018, 9, 1075–1084, doi:10.3762/bjnano.9.99

• absorption; quantum qot filling; self-assembled quantum dots; semi-empirical tight-binding; sp3d5s* with spin–orbit coupling (sp3d5s*_SO); Introduction Self-assembled quantum dots are employed as light absorbers in many optoelectronic devices, such as quantum-dot infrared photodetectors (QDIPs) [1][2], and

An implementation of spin–orbit coupling for band structure calculations with Gaussian basis sets: Two-dimensional topological crystals of Sb and Bi

• Sahar Pakdel,
• Mahdi Pourfath and
• J. J. Palacios

Beilstein J. Nanotechnol. 2018, 9, 1015–1023, doi:10.3762/bjnano.9.94

• . 10.3762/bjnano.9.94 Abstract We present an implementation of spin–orbit coupling (SOC) for density functional theory band structure calculations that makes use of Gaussian basis sets. It is based on the explicit evaluation of SOC matrix elements, both the radial and angular parts. For all-electron basis

• insulator, and to mono- and multilayer Sb(111) (also known as antimonene), the former being a trivial semiconductor and the latter a topological semimetal featuring topologically protected surface states. Keywords: antimonene; electronic structure; Sb few-layers; spin–orbit coupling (SOC); topological

• material; Introduction The topological character of topological materials (mostly insulators but also non-insulators) in most relevant cases originates from relativistic corrections that cannot be neglected in the Hamiltonian of heavy elements, more specifically from spin–orbit coupling (SOC). Such

Revealing the interference effect of Majorana fermions in a topological Josephson junction

• Jie Liu,
• Tiantian Yu and
• Juntao Song

Beilstein J. Nanotechnol. 2018, 9, 520–529, doi:10.3762/bjnano.9.50

• with Rashba spin–orbit coupling and proximity-induced superconductivity appear to be the most promising method [4]. Indeed, a semiconductor–superconductor nanowire was manufactured to confirm the prediction of the theory [12][13][14]. The second topological superconducting system that was realized

Comprehensive investigation of the electronic excitation of W(CO)₆ by photoabsorption and theoretical analysis in the energy region from 3.9 to 10.8 eV

• Mónica Mendes,
• Khrystyna Regeta,
• Filipe Ferreira da Silva,
• Nykola C. Jones,
• Søren Vrønning Hoffmann,
• Gustavo García,
• Chantal Daniel and
• Paulo Limão-Vieira

Beilstein J. Nanotechnol. 2017, 8, 2208–2218, doi:10.3762/bjnano.8.220

• . On the basis of this combined experimental/theoretical study the absorption spectrum of the complex has been totally re-assigned between 3.9 and 10.8 eV under the light of spin–orbit coupling (SOC) effects. The present comprehensive knowledge of the nature of the electronically excited states may be

• based on the 80 lowest excited states has been computed by means of time-dependent density functional theory (TDDFT) [39][40]. Spin–orbit coupling (SOC) effects have been applied as a perturbation to obtain the “spin–orbit” states. All calculations have been performed in vacuum with the ADF2013 code [41

• ), 12t1u, and (LUMO+1), 3t2u, have mainly π*CO antibonding character, while (LUMO+2), 13t1u, and (LUMO+3), 2t1g, have π*CO and σ*CO character, respectively. Interpretation of the experimental data and results from quantum chemical calculations of the lowest electronic states with spin–orbit coupling (SOC

Intercalation of Si between MoS₂ layers

• Rik van Bremen,
• Qirong Yao,
• Soumya Banerjee,
• Deniz Cakir,
• Nuri Oncel and
• Harold J. W. Zandvliet

Beilstein J. Nanotechnol. 2017, 8, 1952–1960, doi:10.3762/bjnano.8.196

• [6]. The broken sub-lattice symmetry of silicene allows for the opening of a band gap in this material [8][9][10][11][12]. This band gap makes silicene a very appealing candidate for field-effect-based devices. Another attractive property of silicene is its spin–orbit coupling, which is substantially

• larger than the spin–orbit coupling in graphene [13][14]. Silicene does not occur in nature and therefore it has to be synthesized. Several studies have reported on the growth of a 2D silicon layer on Ag(111) [15][16][17]. Unfortunately, due to the strong coupling between Si ad-layer and Ag substrate

Transport characteristics of a silicene nanoribbon on Ag(110)

• Ryoichi Hiraoka,
• Chun-Liang Lin,
• Kotaro Nakamura,
• Ryo Nagao,
• Maki Kawai,
• Ryuichi Arafune and
• Noriaki Takagi

Beilstein J. Nanotechnol. 2017, 8, 1699–1704, doi:10.3762/bjnano.8.170

• behaves as a 2D topological insulator (TI) as a result of the sizable spin–orbit coupling of Si [14][15][16]. Silicene grown on solid substrates has been studied intensively. Various superstructures such as (4×4), (2√3×2√3)R30° and (√13×√13) R13.9° are formed on Ag(111) [17][18][19][20][21][22]. These

Spin-chemistry concepts for spintronics scientists

• Konstantin L. Ivanov,
• Alexander Wagenpfahl,
• Carsten Deibel and
• Jörg Matysik

Beilstein J. Nanotechnol. 2017, 8, 1427–1445, doi:10.3762/bjnano.8.143

• electric polarization in chemical processes; a prominent example of theoretical understanding of electric polarization effects is given in the famous Marcus theory [21] of electron transfer. Spin–orbit coupling is not a very prominent issue in spin chemistry of radical pairs because of the absence of heavy

• atoms in most (but not all) of the molecules, for which spin-chemical effects have been studied. Spin–orbit coupling is of importance for the triplet mechanism in spin chemistry and also for triplet state ONP and OEP; these cases are also briefly discussed later. One should also note that the difference

• , Δg, in g-factors of radicals, which is of great importance for spin chemistry, is also due to perturbation terms in the spin Hamiltonian coming from spin−orbit coupling. For spin physicists, however, it might be crucial since it can occur at defects, determining how fast a triplet return to the

Two-dimensional silicon and carbon monochalcogenides with the structure of phosphorene

• Dario Rocca,
• Ali Abboud,
• Ganapathy Vaitheeswaran and
• Sébastien Lebègue

Beilstein J. Nanotechnol. 2017, 8, 1338–1344, doi:10.3762/bjnano.8.135

• in HSE06 calculations electronic eigenvalues have been computed on a 16 × 16 × 1 k-point grid; the band structure was then extracted along the high symmetry directions and interpolated with cubic splines (see below in Figure 3). Spin–orbit coupling often plays an important role in two-dimensional

• , GeS, and GeSe the spin–orbit coupling does not significantly change the shape of bands but gives rise to a splitting of the order of a few tens of millielectronvolts. Due to the high computational cost involved in spin-orbit coupling calculations with the HSE06 functional, this effect has not been

• included in our results. While the inclusion of spin–orbit coupling might slightly affect the values of the gaps and introduce a splitting in some bands, we do not expect a change in the overall conclusions of this work. In the next section we also show results concerning effective masses, of which the

Nanoantenna-assisted plasmonic enhancement of IR absorption of vibrational modes of organic molecules

• Alexander G. Milekhin,
• Olga Cherkasova,
• Sergei A. Kuznetsov,
• Ilya A. Milekhin,
• Ekatherina E. Rodyakina,
• Alexander V. Latyshev,
• Sreetama Banerjee,
• Georgeta Salvan and
• Dietrich R. T. Zahn

Beilstein J. Nanotechnol. 2017, 8, 975–981, doi:10.3762/bjnano.8.99

• mechanism [3], which means that the spin polarization of the carriers can continue for an extended time (in the range from microseconds to milliseconds) [4]. This feature is caused by very low spin–orbit coupling and weak hyperfine interaction. Phthalocyanines (Pcs) are a class of stable, planar small

Single-molecule magnet behavior in 2,2’-bipyrimidine-bridged dilanthanide complexes

• Wen Yu,
• Frank Schramm,
• Eufemio Moreno Pineda,
• Yanhua Lan,
• Olaf Fuhr,
• Jinjie Chen,
• Hironari Isshiki,
• Wolfgang Wernsdorfer,
• Wulf Wulfhekel and
• Mario Ruben

Beilstein J. Nanotechnol. 2016, 7, 126–137, doi:10.3762/bjnano.7.15

• single-ion level [11][12]. SMMs based on 4f ions possess larger thermal energy barriers for magnetization reversal caused by their large single-ion magnetic anisotropy, which originates from spin–orbit coupling and crystal-field splitting of the 4f ions. Technological and structural development of

Effects of spin–orbit coupling and many-body correlations in STM transport through copper phthalocyanine

• Benjamin Siegert,
• Andrea Donarini and
• Milena Grifoni

Beilstein J. Nanotechnol. 2015, 6, 2452–2462, doi:10.3762/bjnano.6.254

• signatures are analyzed. Results and Discussion Microscopic model Hamiltonian for CuPc The focus of this section is the establishment of a minimal model Hamiltonian for an isolated CuPc molecule capable to account for both electron–electron interaction and spin–orbit coupling effects. As discussed below

• Hamiltonian relevant in molecular systems is provided by the SOI. In the following we derive an effective spin–orbit coupling operator acting on the subset of frontier orbitals. The atomic SOI operator reads where α and run over all atoms and shells, respectively. By evaluating Equation 8 only on the

• : where λ1 = 1/2ξCu|cL|2 = 0.47 meV and λ2 = ξCu(cScL)/ = 6.16 meV are now effective spin–orbit coupling constants. A similar analysis of SOI in CuPc, laying more focus on the central Cu atom, can be found in [21]. Finally, many-body eigenenergies ENk and eigenstates , labeled after particle number N and

Silica micro/nanospheres for theranostics: from bimodal MRI and fluorescent imaging probes to cancer therapy

• Shanka Walia and
• Amitabha Acharya

Beilstein J. Nanotechnol. 2015, 6, 546–558, doi:10.3762/bjnano.6.57

• electronic transitions involved are of the type 4fn→4fn−15d1, which accounts for their strong luminescence spectra. Further the high magnetic moment of the lanthanide complexes can be attributed to the spin–orbit coupling of the 4f electrons. Hence, the lanthanides complexes are fluorescent as well as

X-ray photoelectron spectroscopy of graphitic carbon nanomaterials doped with heteroatoms

• Toma Susi,
• Thomas Pichler and
• Paola Ayala

Beilstein J. Nanotechnol. 2015, 6, 177–192, doi:10.3762/bjnano.6.17

• level, each core state is expected to split into two components due to spin–orbit coupling, corresponding to orbital angular momentum quantum numbers of j = 1/2 and 3/2. The magnitude of the spin–orbit splitting is thought to be rather insensitive to the chemical environment and predicted by theory to

Influence of the supramolecular architecture on the magnetic properties of a Dy^III single-molecule magnet: an ab initio investigation

• Julie Jung,
• Olivier Cador,
• Kevin Bernot,
• Fabrice Pointillart,
• Javier Luzon and
• Boris Le Guennic

Beilstein J. Nanotechnol. 2014, 5, 2267–2274, doi:10.3762/bjnano.5.236

• Douglas–Kroll Hamiltonian. First, the scalar terms were included in the basis-set generation and were used to determine the spin-free wavefunctions and energies in the complete active space self consistent field (CASSCF) method [49]. Next, spin-orbit coupling was added within the restricted-active-space

• calculations were performed for all of the sextets (21 roots) and quadruplets (224 roots) of the Dy ion. Only 148 quadruplets were added to the 21 sextets to mix through spin–orbit coupling in RASSI-SO. In this case, there was no need to add more quadruplet or doublet roots to converge the wavefunctions and

Magnetic anisotropy of graphene quantum dots decorated with a ruthenium adatom

• Igor Beljakov,
• Velimir Meded,
• Franz Symalla,
• Karin Fink,
• Sam Shallcross and
• Wolfgang Wenzel

Beilstein J. Nanotechnol. 2013, 4, 441–445, doi:10.3762/bjnano.4.51

• adsorption at the edges. Considering the higher spin-orbit coupling of 4d TMs compared to 3d TMs, as well as the fact that the first observation of 4d ferromagnetism was made for a ruthenium monolayer on a graphite substrate [18], Ru appeared as an attractive candidate for the adatom. All of these reasons

• polarisation of the absorbed Ru atom and this in turn governs the value of EIO. This is, in fact, a rather natural result as the physics of anisotropy is, upon expansion of the Dirac equation in powers of v/c, governed by the spin–orbit coupling term which is proportional to with the spin moment. Having

In situ monitoring magnetism and resistance of nanophase platinum upon electrochemical oxidation

• Eva-Maria Steyskal,
• Stefan Topolovec,
• Stephan Landgraf,
• Heinz Krenn and
• Roland Würschum

Beilstein J. Nanotechnol. 2013, 4, 394–399, doi:10.3762/bjnano.4.46

• due to spin–orbit coupling. Keywords: electrical resistance; electrochemistry; magnetism; porous nanocrystalline Pt; tunable properties; Introduction Porous nanophase materials with electrochemically induced tunability of properties [1] have become a topic of growing research interest in the past

• known for surfaces, the asymmetric potential drop at a surface causes strong spin–orbit coupling with mobile spins (Rashba effect) [21]. This is reflected by the formation of an effective magnetic field due to unbalanced orbital currents, which polarizes the electron spins. Since this Rashba spin–orbit

• nanophase systems according to recent theoretical studies of Subkow and Fähnle [23]. Spin–orbit coupling in combination with potential-dependent surface stress or charge-induced relaxation of the outermost atomic layer may also influence the magnetization, as suggested by Ghosh [14]. More detailed in situ

P-wave Cooper pair splitting

• Henning Soller and
• Andreas Komnik

Beilstein J. Nanotechnol. 2012, 3, 493–500, doi:10.3762/bjnano.3.56

• ) refers to the electron field operator of the superconductor introduced in Equation 5 in position space. Finally, we need a Hamiltonian approach [46] for spin-active scattering. There are manifold effects, such as spin–orbit coupling, magnetic anisotropy or spin relaxation, that give rise to spin-activity