Two-dimensional semiconductors pave the way towards dopant-based quantum computing

• José Carlos Abadillo-Uriel,
• Belita Koiller and
• María José Calderón

Beilstein J. Nanotechnol. 2018, 9, 2668–2673, doi:10.3762/bjnano.9.249

• four possible orbital states (see Supporting Information File 1). We label the expectation values of the Hamiltonian for these states in increasing order E1, E2, E3 and E4, and assign a spin hamiltonian to this problem if such that only the two lowest levels are relevant at low temperatures, and the

Directional light beams by design from electrically driven elliptical slit antennas

• Shuiyan Cao,
• Eric Le Moal,
• Quanbo Jiang,
• Aurélien Drezet,
• Serge Huant,
• Jean-Paul Hugonin,
• Gérald Dujardin and
• Elizabeth Boer-Duchemin

Beilstein J. Nanotechnol. 2018, 9, 2361–2371, doi:10.3762/bjnano.9.221

• ., elliptical spirals, in order to control the optical orbital angular moment of the emitted light beams [50][51]. Experimental Figure 10 shows a schematic representation of the experimental setup. It consists of a commercial STM head (JPK Instruments, NanoWizard 3) mounted on top of an inverted optical

Intrinsic ultrasmall nanoscale silicon turns n-/p-type with SiO₂/Si₃N₄-coating

• Dirk König,
• Daniel Hiller,
• Noël Wilck,
• Birger Berghoff,
• Merlin Müller,
• Sangeeta Thakur,
• Giovanni Di Santo,
• Luca Petaccia,
• Joachim Mayer,
• Sean Smith and
• Joachim Knoch

Beilstein J. Nanotechnol. 2018, 9, 2255–2264, doi:10.3762/bjnano.9.210

• without doping, thereby avoiding all dopant-related issues mentioned above. Such conductivity can be induced by an energy offset (ΔE) of the same electronic states (lowest unoccupied molecular orbital (LUMO) or highest occupied molecular orbital (HOMO)) between different regions of the same usn-Si system

• of information on h-DFT accuracy as compared to experiment, details of UPS measurements and NEGF are contained in Supporting Information File 1. Experimental h-DFT material calculations Hybrid-DFT calculations were carried out in real space with a molecular orbital basis set (MO-BS) and both Hartree

The role of adatoms in chloride-activated colloidal silver nanoparticles for surface-enhanced Raman scattering enhancement

• Nicolae Leopold,
• Andrei Stefancu,
• Krisztian Herman,
• István Sz. Tódor,
• Stefania D. Iancu,
• Vlad Moisoiu and
• Loredana F. Leopold

Beilstein J. Nanotechnol. 2018, 9, 2236–2247, doi:10.3762/bjnano.9.208

• cross-section of the adsorbed molecule. The charge-transfer electronic transition can be explained as follows [8][12][13][14]: The chemical mechanism of SERS involves the absorption of a photon and the excitation of an electron from the Fermi level of the metallic nanoparticle (M) to the LUMO orbital

Influence of the thickness of an antiferromagnetic IrMn layer on the static and dynamic magnetization of weakly coupled CoFeB/IrMn/CoFeB trilayers

• Deepika Jhajhria,
• Dinesh K. Pandya and
• Sujeet Chaudhary

Beilstein J. Nanotechnol. 2018, 9, 2198–2208, doi:10.3762/bjnano.9.206

• measurements) in Equation 2 to obtain g and 4πMeff values as fitting parameters [41][44]. The resulting g values in the films (Figure 4b) are comparable to the already reported g-factor values for CoFeB thin films, and the higher values are associated with larger orbital contributions due to the presence of

Interaction-induced zero-energy pinning and quantum dot formation in Majorana nanowires

• Samuel D. Escribano,
• Alfredo Levy Yeyati and
• Elsa Prada

Beilstein J. Nanotechnol. 2018, 9, 2171–2180, doi:10.3762/bjnano.9.203

• some critical Zeeman field without the expected oscillatory pattern [12][19][24][25]. Several mechanisms have been proposed to account for the reduction or lack of oscillations, such as smooth confinement [21][26][27][28], strong spin–orbit coupling [29], position-dependent pairing [30], orbital

• Majorana energy splitting. Different mechanisms can reduce this splitting, such as interactions with the environment as studied here, smooth potential or gap profiles [21][26][27][28][30], or orbital magnetic effects [31], and still leave the Majorana overlap unaffected. The behavior of the Majorana wave

Spin-coated planar Sb₂S₃ hybrid solar cells approaching 5% efficiency

• Pascal Kaienburg,
• Benjamin Klingebiel and
• Thomas Kirchartz

Beilstein J. Nanotechnol. 2018, 9, 2114–2124, doi:10.3762/bjnano.9.200

• Sb2S3 cells by the polymer is to a large extent parasitic [27]. The applied polymers differ in band gap as can be seen from the measured absorption spectra in Figure 4c and the position of the highest occupied molecular orbital (HOMO). The HOMO of Sb2S3 obtained from ultraviolet photon spectroscopy (UPS

A scanning probe microscopy study of nanostructured TiO₂/poly(3-hexylthiophene) hybrid heterojunctions for photovoltaic applications

• Laurie Letertre,
• Roland Roche,
• Olivier Douhéret,
• Hailu G. Kassa,
• Denis Mariolle,
• Nicolas Chevalier,
• Łukasz Borowik,
• Philippe Dumas,
• Benjamin Grévin,
• Roberto Lazzaroni and
• Philippe Leclère

Beilstein J. Nanotechnol. 2018, 9, 2087–2096, doi:10.3762/bjnano.9.197

• , irrespective of the location where the excitons are generated, they will be able to reach the TiO2/P3HT-COOH interface, and dissociate by transferring an electron from P3HT into the conduction band of TiO2. An accumulation of holes in the highest occupied molecular orbital (HOMO) of P3HT and electrons in the

• illumination. Evac, Ec, Ev, Ef and Φ stand for vacuum level, conduction band, valence band, Fermi level and workfunction, respectively. HOMO and LUMO mean highest occupied molecular orbital and lowest unoccupied molecular orbital, respectively. (a) 400 × 400 nm2 AFM height image obtained in air on a TiO2/P3HT

Metal-free catalysis based on nitrogen-doped carbon nanomaterials: a photoelectron spectroscopy point of view

• Mattia Scardamaglia and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2018, 9, 2015–2031, doi:10.3762/bjnano.9.191

• , the latter has only two neighboring carbon atoms to form two σ-bonds. One electron occupies the pz-orbital and the other two form an electron lone pair without occupying the π*-band. Therefore, pyridinic nitrogen does not behave as an electron dopant. Instead, the pyridinic vacancy complex has a hole

• decreases with all types of nitrogen species, but graphitic nitrogen and Stone–Wales defects are more efficient than pyridinic nitrogen. In fact, the latter was shown to have a negligible occupation of the π*-anti-bonding orbital, due to its two-fold coordination and the lone-pair electrons, in contrast to

• because the energy difference between the Fermi level and the unoccupied 2p orbital state in the adsorbed oxygen molecule is reduced. Furthermore, the ORR pathway in the presence of nitrogen is a four-electron reduction process, instead of the less efficient two-electron process in the pristine graphene

Numerical analysis of single-point spectroscopy curves used in photo-carrier dynamics measurements by Kelvin probe force microscopy under frequency-modulated excitation

• Pablo A. Fernández Garrillo,
• Benjamin Grévin and
• Łukasz Borowik

Beilstein J. Nanotechnol. 2018, 9, 1834–1843, doi:10.3762/bjnano.9.175

• molecular orbital of the molecule to the lowest unoccupied molecular orbital in the case of organic photovoltaics), thus leaving a hole behind that can be considered as a positive charge. Recombination is the opposed process where negative and positive charges recombine and are annihilated. In both cases

A visible-light-controlled platform for prolonged drug release based on Ag-doped TiO₂ nanotubes with a hydrophobic layer

• Caihong Liang,
• Jiang Wen and
• Xiaoming Liao

Beilstein J. Nanotechnol. 2018, 9, 1793–1801, doi:10.3762/bjnano.9.170

• solution placed in 10 mL centrifuge tubes to wash off the Zn2+ substance loosely attached to the surfaces. The sample was placed into plastic centrifuge tubes. Then the surfaces were immersed in 5 mL of PBS at room temperature with orbital shaking. 5 mL of solution was taken after specific interval times

A zero-dimensional topologically nontrivial state in a superconducting quantum dot

• Pasquale Marra,
• Alessandro Braggio and
• Roberta Citro

Beilstein J. Nanotechnol. 2018, 9, 1705–1714, doi:10.3762/bjnano.9.162

• consider a semiconducting quantum dot in a magnetic field B and coupled with two superconducting leads, as shown in Figure 1. We assume that the only effect of the magnetic field is the lifting of the spin degeneracy via the Zeeman effect, and we neglect orbital effects of the field. Moreover, we assume

Free-radical gases on two-dimensional transition-metal disulfides (XS₂, X = Mo/W): robust half-metallicity for efficient nitrogen oxide sensors

• Chunmei Zhang,
• Yalong Jiao,
• Fengxian Ma,
• Sri Kasi Matta,
• Steven Bottle and
• Aijun Du

Beilstein J. Nanotechnol. 2018, 9, 1641–1646, doi:10.3762/bjnano.9.156

• . The binding position and adsorption energy are analyzed in detail. In terms of the projected density of states (PDOS) and orbital contribution, our results offer a deep insight into the Fermi-level pinning mechanism. In addition, we expand the calculations to other 2D layered materials including GaS

• . However, they failed to point out the spin-polarized Fermi-level pinning in gas/2D nanomaterial system. Based on this, we take the single-layer WS2 as an example to elucidate the different Fermi-level pinning processes of adsorption of NO and NO2. The spin orbital-resolved band structures are simulated

• (Figure 3) and the Fermi level of the adsorbed gas (NO and NO2)/WS2 nanomaterial system is pinned around the lowest unoccupied molecular orbital (LUMO) or highest occupied molecular orbital (HOMO) of the adsorbed gas molecules. The PDOS for WS2 with adsorbed NO indicates that the W and S atoms have no

Robust topological phase in proximitized core–shell nanowires coupled to multiple superconductors

• Tudor D. Stanescu,
• Anna Sitek and
• Andrei Manolescu

Beilstein J. Nanotechnol. 2018, 9, 1512–1526, doi:10.3762/bjnano.9.142

• lowest energy states are localized on the outer edges of the shell, which strongly inhibits the orbital effects of the longitudinal magnetic field that are detrimental to Majorana physics. Using a tight-binding model of coupled parallel chains, we calculate the topological phase diagram of the hybrid

• the crystal structure [27]. The finite cross section of the wires used in the experiments may generate additional phenomena, which are not captured by ideal 1D models. In particular, the orbital effects of the magnetic field, which is oriented parallel to the nanowire, may reduce or even destroy the

• stability of the Majorana modes [28]. Proximitized core–shell nanowires are slightly more complex systems recently shown [29] to have interesting Majorana physics that is practically immune to orbital effects. With a conductive shell and an insulating core, such heterostructures become tubular conductors

Excitation of nonradiating magnetic anapole states with azimuthally polarized vector beams

• Aristeidis G. Lamprianidis and
• Andrey E. Miroshnichenko

Beilstein J. Nanotechnol. 2018, 9, 1478–1490, doi:10.3762/bjnano.9.139

• into Fourier series with respect to the azimuthal angle γ. So, due to its 2π-periodicity, we have: , which is an expansion into modes with different orbital angular momentum m. Then, we can also perform the integration over the azimuthal angle analytically. This yields the simplified formula of

• condition . This implies that the orbital angular momentum m of the input beams before their focusing is bequeathed to the azimuthal quantum number of the multipolar expansion of the focused beams with respect to such a reference frame. This would mean, for example, that a focused beam with m = 3 would bear

• orbital angular momentum: m = 0, bears only multipoles of magnetic type for particles that are located over the optical axis. Moreover, it was also proven that if this particle has a rotational symmetry as well, it will only scatter multipoles of magnetic type. So, it will have a purely magnetic response

Predicting the strain-mediated topological phase transition in 3D cubic ThTaN₃

• Chunmei Zhang and
• Aijun Du

Beilstein J. Nanotechnol. 2018, 9, 1399–1404, doi:10.3762/bjnano.9.132

• %. Interestingly, the effect of spin–orbital coupling (SOC) is significant, leading to a band gap reduction of 0.26 eV in the ThTaN3 compound. Moreover, the strong SOC can turn ThTaN3 into a topological insulator with a large inverted gap up to 0.25 eV, which can be primarily attributed to the inversion between

• the d-orbital of the heavy element Ta and the p-orbital of N. Our results highlight a new 3D topological insulator with strain-mediated topological transition for potential applications in future spintronics. Keywords: Dirac cone; strain; ThTaN3; topological insulator; Introduction The ThTaN3

• , by tuning the SOC strength, we predict that the topological feature actually starts to show up at a 5% compressive strain. The strain-mediated topological phase transition in the perovskite ThTaN3 compound is attributed to band inversion between the d-orbital of the heavy elements and the p-orbital

Disorder-induced suppression of the zero-bias conductance peak splitting in topological superconducting nanowires

• Jun-Tong Ren,
• Hai-Feng Lü,
• Sha-Sha Ke,
• Yong Guo and
• Huai-Wu Zhang

Beilstein J. Nanotechnol. 2018, 9, 1358–1369, doi:10.3762/bjnano.9.128

• interactions between the bound charges in the dielectric surroundings and the free charges in the nanowire [55], a finite leakage out of the Majorana modes due to the presence the normal drain [59], a finite coherence length in the induced superconducting pairing [60], and the orbital magnetic effects [61

Proximity effect in a two-dimensional electron gas coupled to a thin superconducting layer

• Christopher Reeg,
• Daniel Loss and
• Jelena Klinovaja

Beilstein J. Nanotechnol. 2018, 9, 1263–1271, doi:10.3762/bjnano.9.118

• the application of an out-of-plane magnetic field [4][5] (though orbital effects are not incorporated here) or due to the proximity of a magnetic insulator [8]. Also, it is possible to apply an in-plane magnetic field (to avoid unwanted orbital effects) to reach the topological phase if the 2DEG has a

Inverse proximity effect in semiconductor Majorana nanowires

• Alexander A. Kopasov,
• Ivan M. Khaymovich and
• Alexander S. Mel'nikov

Beilstein J. Nanotechnol. 2018, 9, 1184–1193, doi:10.3762/bjnano.9.109

• orbital or paramagnetic mechanism. The suppression of the homogeneous superconducting state near the boundary between the topological and non-topological regimes provides the conditions favorable for the Fulde–Ferrel–Larkin–Ovchinnikov instability. Keywords: inverse proximity effect; Majorana fermions

• magnetic field can only be maintained up to the upper critical field associated with either orbital or intrinsic paramagnetic effect in the S shell. The suppression of the superconducting order parameter near the line of transition between the topologically trivial and nontrivial phases can result in one

• shell into the point y in the wire and back with the amplitude . It is important to note that here we do not consider the orbital effects in the superconducting shell. This approximation imposes some restrictions on the value of magnetic fields under consideration, which are nevertheless quite realistic

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

• obtain correct biaxial strain ratios in quantum wells is shown here to improve the accuracy of quantum dot simulations as compared with experimental measurements. The Hamiltonian is constructed with semi-empirical tight-binding with 20-orbital sp3d5s* basis per atom, including spin–orbit interaction

• electrons and holes. It is worth noting that the hole ground state has an s-orbital-like shape. QDs have a complicated band profile since multiple effects such as geometric confinement, strain and alloy disorder, can cause major changes in the band edges of the bulk material. It is important to know where

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

• working with localized basis sets, it is crucial to choose a large enough number of elements or a set of properly chosen ones. Typically, the basis functions are centered on atoms, and are so called ”atomic orbitals”. Two types of atomic orbital functions are typically employed in molecular orbital

• part, yield to lowest order a SOC correction of the form (see, e.g., [31] for a nice overview of a fairly extensive topic) which mixes orbital angular momentum (m) and spin (σ) quantum numbers. Since the angular and radial parts of the wave functions are orthogonal, SOC matrix elements between

• orbital dependent charge term (placed at the origin) to the bare nuclear potential [32]. The effective potential can also be extracted from an atomic DFT calculation. Here, we explored both possibilities and found no significant differences. A correct electronic band structure in solids requires an

Cyclodextrin inhibits zinc corrosion by destabilizing point defect formation in the oxide layer

• Abdulrahman Altin,
• Maciej Krzywiecki,
• Adnan Sarfraz,
• Cigdem Toparli,
• Claudius Laska,
• Philipp Kerger,
• Aleksandar Zeradjanin,
• Karl J. J. Mayrhofer,
• Michael Rohwerder and
• Andreas Erbe

Beilstein J. Nanotechnol. 2018, 9, 936–944, doi:10.3762/bjnano.9.86

• shift for all energy regions [35], as opposed to what is observed. Since the XPS was not sensitive for the region of the highest occupied molecular orbital (HOMO) of β-CD, this region was analyzed by UPS. Figure 3f presents the magnification of the low-energy onset of the UP spectra, which allows for

Facile synthesis of a ZnO–BiOI p–n nano-heterojunction with excellent visible-light photocatalytic activity

• Mengyuan Zhang,
• Jiaqian Qin,
• Pengfei Yu,
• Bing Zhang,
• Mingzhen Ma,
• Xinyu Zhang and
• Riping Liu

Beilstein J. Nanotechnol. 2018, 9, 789–800, doi:10.3762/bjnano.9.72

• semiconductor’s band gap. Bismuth(III)-containing semiconductors (such as bismuth oxide [17], bismuth vanadate [18][19], bismuth tungstate [20], bismuth perovskite [21], bismuth molybdate [22], etc.) have been extensively researched as a broad hybrid orbital composed of Bi 6s in the field of photocatalysis

Mechanistic insights into plasmonic photocatalysts in utilizing visible light

• Kah Hon Leong,
• Azrina Abd Aziz,
• Lan Ching Sim,
• Pichiah Saravanan,
• Min Jang and
• Detlef Bahnemann

Beilstein J. Nanotechnol. 2018, 9, 628–648, doi:10.3762/bjnano.9.59

• observed using a light microscope [125][126]. Finally, since the 1O2 species possess paramagnetic properties caused by the orbital angular momentum, they can be quantified by direct ESR detection [127]. Therefore, an ESR spectrometer with a microwave frequency of about 9 GHz (X-band) could be used to

Electron interactions with the heteronuclear carbonyl precursor H₂FeRu₃(CO)₁₃ and comparison with HFeCo₃(CO)₁₂: from fundamental gas phase and surface science studies to focused electron beam induced deposition

• Ragesh Kumar T P,
• Paul Weirich,
• Lukas Hrachowina,
• Marc Hanefeld,
• Ragnar Bjornsson,
• Helgi Rafn Hrodmarsson,
• Sven Barth,
• D. Howard Fairbrother,
• Michael Huth and
• Oddur Ingólfsson

Beilstein J. Nanotechnol. 2018, 9, 555–579, doi:10.3762/bjnano.9.53

• required for theoretical treatment and calculation of orbital energies for the electronic ground state (highest occupied molecular orbital; HOMO) and as a base for calculations of the singly occupied molecular orbital (SOMO) energy of the respective anion formed upon electron attachment. Thus, in context