Molecular nanoarchitectonics: unification of nanotechnology and molecular/materials science

• Katsuhiko Ariga

Beilstein J. Nanotechnol. 2023, 14, 434–453, doi:10.3762/bjnano.14.35

• tip was brought close enough to obtain a single-atom conductance gap, it was retracted and silicon atoms were removed. A perpendicular magnetic field was applied to explore physical phenomena such as Kondo resonance. The nanoarchitectonics of magnetic topological states due to spin polarization in

Spin dynamics in superconductor/ferromagnetic insulator hybrid structures with precessing magnetization

• Yaroslav V. Turkin and
• Nataliya Pugach

Beilstein J. Nanotechnol. 2023, 14, 233–239, doi:10.3762/bjnano.14.22

• magnetization precession and proximity effect can suppress superconductivity at the interface causing an increasing number of quasiparticles. To explore the spin dynamics of the quasiparticles more deeply, let us investigate spin components of the electron block of the distribution function. Spin polarization

• of quasiparticles can be obtained by applying a spin polarization operator to the distribution function matrix. Due to the block-diagonal structure of the spin operator in electron–hole space, the spin distribution of quasiparticles can be represented as a superposition of electron-like and hole-like

• spin distributions . The first term in this expression corresponds to the spin polarization of electron-like quasiparticles and is mathematically equivalent to the trace of the product of Pauli matrix and the left upper block of the distribution matrix. Figure 4 illustrates the dynamics of the

Design of surface nanostructures for chirality sensing based on quartz crystal microbalance

• Yinglin Ma,
• Xiangyun Xiao and
• Qingmin Ji

Beilstein J. Nanotechnol. 2022, 13, 1201–1219, doi:10.3762/bjnano.13.100

• that the induced spin polarization may affect enantiorecognition under an external field. They experimentally showed that the interaction of chiral molecules with a perpendicularly magnetized substrate was enantiospecific (Figure 12) [145]. The spin-specific interactions between magnetic metals and

Theoretical investigations of oxygen vacancy effects in nickel-doped zirconia from ab initio XANES spectroscopy at the oxygen K-edge

• Dick Hartmann Douma,
• Lodvert Tchibota Poaty,
• Alessio Lamperti,
• Stéphane Kenmoe,
• Abdulrafiu Tunde Raji,
• Alberto Debernardi and
• Bernard M’Passi-Mabiala

Beilstein J. Nanotechnol. 2022, 13, 975–985, doi:10.3762/bjnano.13.85

• contribution to the pre-edge peak is mainly due to its 3dxy, 3dzx, and 3dzy spin-down orbitals, as well as its 3dzy spin-up orbitals, as shown by the PDOS in Figure 4a. Ni1 with Ni4+ oxidation state and 3d6 orbital configuration has a tetrahedral coordination, which suggests that it is in low spin-polarization

• spin-polarization, as well as an oxidation state similar to that of the Ni1 atom. Also, its orbital contribution to the pre-edge peak is similar to that of Ni1. For the structure S1, the O K-edge spectrum (calculated from the average of 63 O K-edge spectra) shows a pre-edge peak in the same energy

• and spin-down orbitals (Figure 4c). This orbital arrangement suggests that the nickel atom has an oxidation state of +3 and is in high spin-polarization with the valence electron configuration according to ligand field theory (cf. Figure 2). In the case of nickel atom Ni2, the contribution to the O

Spontaneous shape transition of Mn_xGe_1−x islands to long nanowires

• S. Javad Rezvani,
• Luc Favre,
• Gabriele Giuli,
• Yiming Wubulikasimu,
• Isabelle Berbezier,
• Augusto Marcelli,
• Luca Boarino and
• Nicola Pinto

Beilstein J. Nanotechnol. 2021, 12, 366–374, doi:10.3762/bjnano.12.30

• silicides as an indispensable part of microelectronics [14][15]. In particular, the manganese germanide phase Mn5Ge3 is a semimetallic compound that has attracted attention due to its giant magnetoresistance and large spin polarization, which make it a proper candidate for spintronics applications [16][17

Kondo effects in small-bandgap carbon nanotube quantum dots

• Patryk Florków,
• Damian Krychowski and
• Stanisław Lipiński

Beilstein J. Nanotechnol. 2020, 11, 1873–1890, doi:10.3762/bjnano.11.169

• . In the 1e region there are a spin Kondo effect with the fluctuating states |0↓⟩ and |0↑⟩ exhibiting orbital polarization, a valley Kondo effect with the |0↓⟩ and |↓0⟩ states exhibiting spin polarization, and a spin–valley Kondo effect with fluctuations of |↓0⟩ and |0↑⟩, in which both spin and orbital

• the SU(4) point in the 1e valley and the SU(3) point in the 3e valley. As already mentioned, the examples presented above do not exhaust all possible locations of high-symmetry points. Figure 3a presents an example of spin polarization of conductance corresponding to the conduction map in Figure 2c

• plotted ground-state diagrams of (a) CNTQD(24,21), (b) CNTQD(39,24), (c) CNTQD(15,12), and d) CNTQD(48,18) (U = 6 meV, Γ = 0.03 meV, δ = 1 meV·nm, β = 37 meV·nm2). (a, b) Spin polarization (SPC) and orbital polarization (OPC) maps of CNTQD(15,12). (c, d) Spin (MZ) and orbital pseudospin (TZ) magnetization

Epitaxial growth and superconducting properties of thin-film PdFe/VN and VN/PdFe bilayers on MgO(001) substrates

• Wael M. Mohammed,
• Igor V. Yanilkin,
• Amir I. Gumarov,
• Airat G. Kiiamov,
• Roman V. Yusupov and
• Lenar R. Tagirov

Beilstein J. Nanotechnol. 2020, 11, 807–813, doi:10.3762/bjnano.11.65

• magnetically soft, tunable and weak in the sense of small spin-polarization of the conduction band [10][28]. The latter provides a large superconducting coherence length and hence bypasses a necessity to deposit flat, nanometer-thick continuous layers expected for strong elemental ferromagnets. A combination

Hexagonal boron nitride: a review of the emerging material platform for single-photon sources and the spin–photon interface

• Stefania Castelletto,
• Faraz A. Inam,
• Shin-ichiro Sato and
• Alberto Boretti

Beilstein J. Nanotechnol. 2020, 11, 740–769, doi:10.3762/bjnano.11.61

Nitrogen-vacancy centers in diamond for nanoscale magnetic resonance imaging applications

• Alberto Boretti,
• Lorenzo Rosa,
• Jonathan Blackledge and
• Stefania Castelletto

Beilstein J. Nanotechnol. 2019, 10, 2128–2151, doi:10.3762/bjnano.10.207

• -labeled probes (such as 13C pyruvate) has best enabled the monitoring of core cellular metabolic events. Hyperpolarized molecular compounds are obtained, for example, from carbon-13-containing molecules. This is done by transferring the electron spin polarization to the 13C nuclei at cryogenic

• effect is used which is a proton–electron polarization transfer technique. The process transfers the spin polarization from paramagnetic impurities within NDs and the surfaces to 1H spins in the surrounding water solution (cross-polarization sequences). This is known as Overhauser-enhanced MRI (OMRI) and

• detectable by conventional EPR methods. The procedure involves an AC RF magnetic field in resonance with the EPR spin frequency, driving the ND electron spin polarization which is then transferred to the interacting 1H nuclei in the water containing the ND. 1H nuclei resonance is then detected by using a

Giant magnetoresistance ratio in a current-perpendicular-to-plane spin valve based on an inverse Heusler alloy Ti₂NiAl

• Yu Feng,
• Zhou Cui,
• Bo Wu,
• Jianwei Li,
• Hongkuan Yuan and
• Hong Chen

Beilstein J. Nanotechnol. 2019, 10, 1658–1665, doi:10.3762/bjnano.10.161

• largest interface spin polarization of ≈55%. Our study on spin-transport properties indicates that the total transmission coefficient at the Fermi level mainly comes from the contribution from the spin up electrons, which are regarded as the majority of the spin electrons. When the two electrodes of the

• metallicity, while minority spin bands possess an energy gap around the Fermi level. Such a novel band structure results in a theoretical 100% spin polarization, which is one of the most crucial parameters for CPP-SV according to the Valet–Fert model [5]. As one of the subfamilies of Heusler alloys

• presents a small negative value. Because the interface spin polarization (ISP) plays an important role in determining the performance of a spin-dependent device, the interfacial electronic structure is calculated and exhibited in Figure 3, where the left panel and right panel indicate the interfacial

Superconducting switching due to a triplet component in the Pb/Cu/Ni/Cu/Co₂Cr_1−xFe_xAl_y spin-valve structure

• Andrey Andreevich Kamashev,
• Nadir Nurgayazovich Garif’yanov,
• Aidar Azatovich Validov,
• Joachim Schumann,
• Vladislav Kataev,
• Bernd Büchner,
• Yakov Victorovich Fominov and
• Ilgiz Abdulsamatovich Garifullin

Beilstein J. Nanotechnol. 2019, 10, 1458–1463, doi:10.3762/bjnano.10.144

• = Co2Cr1−xFexAly with a high degree of spin polarization (DSP) of the conduction band and a Ni layer of variable thickness. The separation between the superconducting transition curves measured for the parallel (α = 0°) and perpendicular (α = 90°) orientation of the magnetization of the HA and the Ni

• contact spectroscopy [16], has a 90% polarization of the conduction band, we have chosen as a drawing layer for LRTC the HA Co2Cr1−xFexAly with a spin polarization of the conduction band of ≥70% [17] and instead of MoGe as an S layer we have used the elemental superconductor Pb. Sample Preparation and

• Experimental Results We prepared several sets of the F1/F2/S spin-valve structures containing HA = Co2Cr1−xFexAly with the high degree of spin polarization (DSP) of the conduction band standing for the F1 layer adapting the preparation method from [17]. The grown heterostructures have the following composition

Electronic and magnetic properties of doped black phosphorene with concentration dependence

• Ke Wang,
• Hai Wang,
• Min Zhang,
• Yan Liu and
• Wei Zhao

Beilstein J. Nanotechnol. 2019, 10, 993–1001, doi:10.3762/bjnano.10.100

• structures of Si- and S-doped phosphorene without spin polarization always show metallic states suggesting the bandgap is insensitive to the in-plane size of the supercell and the dopant content. However, the results are fairly different once the spin polarization is taken into account. The band structures

• supercell size due to decreasing deformation and dopant content. In the following, we discuss the magnetic and electronic properties of the stable doped phosphorenes induced by the deformation and impurity concentration. Band structure without spin polarization Before investigating the magnetic properties

• , the electronic structures of the Si- and S-doped phosphorenes were calculated, first without considering spin polarization. The results are shown in Figure 2 where the magenta lines represent the impurity levels and the Fermi level is shifted to zero. The impurity states induced by the Si and S atoms

Improved catalytic combustion of methane using CuO nanobelts with predominantly (001) surfaces

• Qingquan Kong,
• Yichun Yin,
• Bing Xue,
• Yonggang Jin,
• Wei Feng,
• Zhi-Gang Chen,
• Shi Su and
• Chenghua Sun

Beilstein J. Nanotechnol. 2018, 9, 2526–2532, doi:10.3762/bjnano.9.235

• forms, but spin-polarization for lowly coordinated Cu on the surface and radicals involved in CH4 oxidation deserves serious consideration. For instance, the difference in calculated adsorption energies with and without spin-polarization can be as high as 0.1–0.2 eV, with geometries showing slight

• reactant to product). Based on our tests, both spin-polarization and vdW corrections are necessary, especially for the calculation of intermediate radicals involved in CH4 oxidation (e.g., CH2*, CH* and O*). During the quick screening of surfaces for CH4 adsorption, the adsorption energy (AE) and

High-temperature magnetism and microstructure of a semiconducting ferromagnetic (GaSb)_1−x(MnSb)_x alloy

• Leonid N. Oveshnikov,
• Elena I. Nekhaeva,
• Alexey V. Kochura,
• Alexander B. Davydov,
• Mikhail A. Shakhov,
• Sergey F. Marenkin,
• Oleg A. Novodvorskii,
• Alexander P. Kuzmenko,
• Alexander L. Vasiliev,
• Boris A. Aronzon and
• Erkki Lahderanta

Beilstein J. Nanotechnol. 2018, 9, 2457–2465, doi:10.3762/bjnano.9.230

• doped by Mn [1][2][3]. Among these systems, the most well-known and extensively studied is Ga1−xMnxAs. Here Mn atoms substitute Ga atoms and establish a ferromagnetic state realized through carrier-induced indirect exchange between Mn atoms by a Zener–RKKY mechanism accompanied by the spin polarization

• was suggested [9] that the ferromagnetic ordering in this case is induced by the interaction of MnSb magnetic clusters with carriers inside the matrix. It should induce carrier spin-polarization and lead to the formation of a long-range ferromagnetic percolation cluster, which includes both MnSb

• (electron transport) properties. Therefore, these samples are more suitable to reveal the nature of magnetic properties and hole spin-polarization in this material, which is the aim of this paper. Main parameters of the studied samples are presented in Table 1. Figure 1a shows typical curves of the

Increasing the performance of a superconducting spin valve using a Heusler alloy

• Andrey A. Kamashev,
• Aidar A. Validov,
• Joachim Schumann,
• Vladislav Kataev,
• Bernd Büchner,
• Yakov V. Fominov and
• Ilgiz A. Garifullin

Beilstein J. Nanotechnol. 2018, 9, 1764–1769, doi:10.3762/bjnano.9.167

• /Pb has been investigated in detail with the focus on the S/F proximity effect very recently. It was shown [25] that the degree of the spin polarization of the conduction band of the HA film amounts to 30% for the films prepared at a particular substrate temperature of Tsub = 300 K during the growth

• of the HA layer and to 70% at Tsub = 600 K. In the AFM/F1/N1/F2/N2/S structure it would be advantageous to achieve a penetration depth of the Cooper pairs into F2 ferromagnetic layer as large as possible. This means that the spin polarization of the conduction band should be small. To fulfill this

• layer in a CoOx/F1/Cu/F2/Cu/Pb heterostructure a specially prepared thin film of the Heusler alloy Co2Cr1−xFexAl with a small degree of the spin polarization of the conduction band significantly increases the magnitude of the superconducting spin valve effect ΔTc as compared to similar systems with the

Josephson effect in junctions of conventional and topological superconductors

• Alex Zazunov,
• Albert Iks,
• Miguel Alvarado,
• Alfredo Levy Yeyati and
• Reinhold Egger

Beilstein J. Nanotechnol. 2018, 9, 1659–1676, doi:10.3762/bjnano.9.158

• modeled by a Kitaev chain, the supercurrent vanishes identically [31]. This supercurrent blockade can be traced back to the different (s/p-wave) pairing symmetries for the S/TS leads, together with the fact that MBSs have a definite spin polarization. For an early study of Josephson currents between

• by two TS wires and one S lead, crossed Andreev reflections allow for the nonlocal splitting of Cooper pairs in the S electrode involving both TS wires (or the reverse process). In this way, an equilibrium supercurrent will be generated unless the MBS spin polarization axes of both TS wires are

• ] then rule out a supercurrent for TS wires in the deep topological regime. We show below that unless B is inadvertently aligned with the MBS spin polarization axis, spin mixing will indeed generate a supercurrent. The S/TS leads are coupled to the QD via a tunneling Hamiltonian [70], where ψσ and ψ are

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

• (Figure S3a–d; Supporting Information File 1), we conclude that the N and O p-orbitals result in absolute spin polarization. In the WS2 monolayer with adsorbed NO2, no apparent DOS peaks are present around the Fermi level (Figure 2f). The spatial magnetic charge distribution analysis suggests that all the

• spin polarization (Figure S3c,d; Supporting Information File 1) and the dominant contribution to the HOMO and the LUMO at the Fermi level originates from the p-orbitals of N and O gas atoms (Figure S3a,b; Supporting Information File 1). Therefore, only the p-orbitals of N and O atoms are plotted in

Solid-state Stern–Gerlach spin splitter for magnetic field sensing, spintronics, and quantum computing

• Kristofer Björnson and
• Annica M. Black-Schaffer

Beilstein J. Nanotechnol. 2018, 9, 1558–1563, doi:10.3762/bjnano.9.147

• (1)-AB to SU(2)-AB. Results Setup Consider the conceptual setup in Figure 1. The circular channel around the hole forms an edge of the 2D TI and therefore hosts helical edge states. We assume for simplicity that the spin-polarization axis is perpendicular to the plane of the TI. The Hamiltonian

• only interested in forward propagation of up spins along one edge, and down spins along the other, it is possible to add additional floating ferromagnetic leads with opposite spin polarization to the forward propagating modes to the two edges. This allows for reflected spins to escape without affecting

• reason the middle spin splitter is tilted at an angle π/2 is to make its edge states have their spin-polarization perpendicular to those of the other two. In practice it would therefore be possible to have all three devices in the same plane, if it is constructed out of two different types of 2D TIs with

Interplay between pairing and correlations in spin-polarized bound states

• Szczepan Głodzik,
• Aksel Kobiałka,
• Anna Gorczyca-Goraj,
• Andrzej Ptok,
• Grzegorz Górski,
• Maciej M. Maśka and
• Tadeusz Domański

Beilstein J. Nanotechnol. 2018, 9, 1370–1380, doi:10.3762/bjnano.9.129

• |uin↑|2 −|uin↓|2 at the positive energy ω = +EYSR and of |vin↑|2 −|vin↓|2 at the negative energy ω = −EYSR implies the effective spin-polarization of the bound states (their polarization is illustrated in the bottom panel of Figure 1). For a quantitative estimation of the spatially varying

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

• separates the regimes with trivial and nontrivial topological properties of the system [3][4][18]. Further increase in the magnetic field is known to suppress the proximity effect since in the absence of the spin–orbit coupling the Fermi level crosses the only energy branch with a complete spin polarization

• along the magnetic field direction. The nonzero spin–orbit coupling destroys this spin polarization mixing different spin projections and resulting in a nonzero induced superconducting gap in the wire of approximately αΔind/gβH, where Δind is the induced superconducting order parameter in the wire, and

• standard paramagnetic effect. In contast, in the topologically nontrivial regime Tc increases (with or without initial decay at small fields). This increase in the critical temperature originates from the reduction of the proximity effect due to almost pure spin polarization of quasiparticles in the wire

Dynamics and fragmentation mechanism of (C₅H₄CH₃)Pt(CH₃)₃ on SiO₂ surfaces

• Kaliappan Muthukumar,
• Harald O. Jeschke and
• Roser Valentí

Beilstein J. Nanotechnol. 2018, 9, 711–720, doi:10.3762/bjnano.9.66

• energy cut-off of 400 eV was used and all ions were fully relaxed using a conjugate gradient scheme until the forces were less than 0.01 eV/Å. In the geometry optimizations for the molecule and the surface models the Brillouin zone was sampled at the Γ point only. Spin polarization was considered for all

Electronic structure, transport, and collective effects in molecular layered systems

• Torsten Hahn,
• Tim Ludwig,
• Carsten Timm and
• Jens Kortus

Beilstein J. Nanotechnol. 2017, 8, 2094–2105, doi:10.3762/bjnano.8.209

• structures show some asymmetry between the spin-up and spin-down DOS. Results and Discussion Transport through phthalocyanine heterostructures The ground state calculation results are reflected in the corresponding I–V curves shown in Figure 2a,b together with plots of the spin polarization of the current as

• polarization of the current depends strongly on the applied bias voltage. While for the CoPc/CoPc system the spin polarization vanishes with increasing bias voltage, the F16CoPc/MnPc stack shows maxima of the spin polarization at approximately Vbias = ±0.5 V of over 60% and the polarization does not vanish for

• . However, the F16CoPc/MnPc heterostructure yields a stronger spin polarization of the current, which is predicted not to vanish for high bias voltages. The investigated prototypical TMR device yields a qualitatively consistent picture. The predicted TMR for the F16CoPc/MnPc heterostructure is by a factor

Spin-dependent transport and functional design in organic ferromagnetic devices

• Guichao Hu,
• Shijie Xie,
• Chuankui Wang and
• Carsten Timm

Beilstein J. Nanotechnol. 2017, 8, 1919–1931, doi:10.3762/bjnano.8.192

• hybridization may modify the organic interfacial spin polarization (SP), which has triggered the new concept of “organic spinterface” [5]. Recent experimental studies have demonstrated the reproduction of conventional spintronic devices using organic counterparts, e.g., magnetoresitive devices [6][7][8]. On the

• , and increase the interest in the design of organic spintronic devices with OFs. Schematic of an organic ferromagnetic device. (a) Current–voltage characteristics for a OF device with N = 20 carbon sites. (b) Spin polarization of the current as a function of bias. Reproduced with permission from [31

• ], copyright 2007 American Physical Society. (a) Spin polarization of the current as a function of the spin coupling strength j for a bias of 0.8 V. (b) Bias-dependent spin polarization of the current for three different values of the electron–lattice coupling strength α. Reproduced with permission from [31

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

• -Boltzmann spin polarization which is highly desired by spectroscopists since it enhances the sensitivity of the method. Polarization of electron spins (CIDEP) and nuclear spins (CIDNP) results from spin selectivity of chemical reactions and can be used for sensitive detection of transient radical species

• opposite phase of polarization of the partner radicals avoiding geminate recombination: when the SCRP is singlet-born, no net spin polarization can be formed. The formation of such CIDEP can be explained using the fictitious spin representation of CIDEP, as proposed by Adrian [110]. Other CIDEP mechanisms

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