Absence of free carriers in silicon nanocrystals grown from phosphorus- and boron-doped silicon-rich oxide and oxynitride

• Daniel Hiller,
• Julian López-Vidrier,
• Keita Nomoto,
• Michael Wahl,
• Wolfgang Bock,
• Tomáš Chlouba,
• František Trojánek,
• Sebastian Gutsch,
• Margit Zacharias,
• Dirk König,
• Petr Malý and
• Michael Kopnarski

Beilstein J. Nanotechnol. 2018, 9, 1501–1511, doi:10.3762/bjnano.9.141

• the bottom end of the nanoscale requires different doping approaches that either relocate the dopants in the surrounding matrix (e.g., Si modulation doping by SiO2:Al) [59] or do not require impurities at all (e.g., electrically reconfigurable nanowire-FETs [60] or p/n-behaviour induced by energy

Cr(VI) remediation from aqueous environment through modified-TiO₂-mediated photocatalytic reduction

• Rashmi Acharya,
• Brundabana Naik and
• Kulamani Parida

Beilstein J. Nanotechnol. 2018, 9, 1448–1470, doi:10.3762/bjnano.9.137

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

• square lattice of a superconducting host, (ii) a nanoscopic chain of magnetic impurities on the classical superconductor (i.e., proximitized Rashba nanowire) in its topologically trivial/nontrivial superconducting phase, and (iii) a strongly correlated quantum dot side-attached to the Rashba chain, where

• μN↑ − μN↓. Individual atoms of the nanochain are coupled with such STM tip through For simplicity, we assume constant couplings The low-energy physics of such proximitized Rashba nanowire can be described by [44] where annihilates (creates) an electron of spin σ at site i with energy εi, and tij

• proposals for such nanodevices have been recently discussed by several authors [52][53]. In summary of this section, we emphasize that the Majorana modes coalescing from the YSR states in the proximitized Rashba nanowire are characterized by their magnetic polarization. Indeed, such a feature has been

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

• the peak height. Remarkably, for a longer nanowire, the zero-bias peak could be reproduced by weak disorder for a finite Majorana energy splitting. It is interesting that the shot noise provides a signature to discriminate whether the zero-bias peak is induced by Majorana zero mode or disorder. For

• -matter systems, including p-wave superconductors [10][11], topological insulator-superconductor hybrid structures [12][13], artificially engineered Kitaev chains [14][15], semiconductor-superconductor hybrid nanowire systems [16][17][18][19][20][21]. Very recently, the one-dimensional Majorana mode

• produces a finite Majorana energy splitting and zero-bias peak splitting [36][37][38] due to the finite size effects. In a recent experiment [39], the energy splitting of Majorana zero mode has been observed in InAs nanowire segments with epitaxial aluminium, which forms a proximity-induced superconducting

Andreev spectrum and supercurrents in nanowire-based SNS junctions containing Majorana bound states

• Jorge Cayao,
• Annica M. Black-Schaffer,
• Elsa Prada and
• Ramón Aguado

Beilstein J. Nanotechnol. 2018, 9, 1339–1357, doi:10.3762/bjnano.9.127

• discussed. Further, we identify the individual contribution of MBSs. In short junctions the MBSs determine the current–phase curves, while in long junctions the spectrum above the gap (quasi-continuum) introduces an important contribution. Keywords: hybrid superconductor–semiconductor nanowire

• –superconductor junctions; Josephson effect; Majorana bound states; nanowires; spin–orbit coupling; Zeeman interaction; Introduction A semiconducting nanowire with strong Rashba spin–orbit coupling (SOC) with proximity-induced s-wave superconducting correlations can be tuned into a topological superconductor by

• means of an external Zeeman field [1][2][3]. This topological phase is characterized by the emergence of zero-energy quasiparticles with Majorana character localized at the nanowire ends. These Majorana bound states (MBSs) are attracting a great deal of attention owing to their potential for topological

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

• 2DEG, while δμk,ω corresponds to a tunneling-induced shift in the effective chemical potential of the 2DEG. Quite surprisingly, the self-energy in Equation 14 and Equation 15 coincides with that of a nanowire coupled to a two-dimensional superconductor with finite width as found in [48], with the

Circular dichroism of chiral Majorana states

• Javier Osca and
• Llorenç Serra

Beilstein J. Nanotechnol. 2018, 9, 1194–1199, doi:10.3762/bjnano.9.110

• ][11][12][13][14]. A Majorana mode enhances the zero-bias conductance by allowing a perfect Andreev backscattering at zero excitation energy when the nanowire is attached to a normal lead. These peculiar pairs of states may be seen as nonlocal split fermions, protected by an energy gap that separates

• decays exponentially with the distance to the nanowire end. By contrast, propagating Majorana states with sustained spatial oscillations can be present at the edges and along the perimeter of 2D-like hybrid structures. This is the situation in presence of p + ip superconductivity for spinless

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

• nanowire resulting in its non-trivial energy dependence. Indeed, considering, e.g., a single-channel nanowire we get the DOS diverging as a square root function of the energy relative to the bottom of the conduction band. This van Hove singularity in the DOS should cause a strong energy dependence of the

• Figure 1. Hereafter we use the units with kB = = 1, where kB is the Boltzmann constant, and is the Planck constant. The Hamiltonian of the system reads: with the first term describing the s-wave superconducting shell. corresponds to the Hamiltonian of the nanowire, and the tunnel Hamiltonian takes the

• generalization [17] of the expression for Γw for the case of an arbitrary number of transverse modes in the nanowire assuming also the value 1/υ0 to be averaged over these modes. The resulting ratio of the tunneling rates takes the form: Due to the growth of Ns with the shell thinkness ds in the multi-mode

Thermoelectric current in topological insulator nanowires with impurities

• Sigurdur I. Erlingsson,
• Jens H. Bardarson and
• Andrei Manolescu

Beilstein J. Nanotechnol. 2018, 9, 1156–1161, doi:10.3762/bjnano.9.107

• charge current generated by maintaining a temperature difference over a nanowire at zero voltage bias. For topological insulator nanowires in a perpendicular magnetic field the current can change sign as the temperature of one end is increased. Here we study how this thermoelectric current sign reversal

• insulator material, such as BiSe, is formed into a nanowire, topological states can appear on its surface. Recently, such wires in a magnetic field have been studied extensively both theoretically [20][21][22][23][24] and experimentally [5][6][7][8][9][10][25]. When the nanowires are of circular cross

• method [39]. Experiments on normal (not topological) nanowires show a conductance that can be complicated, but reproducible trace for a given nanowire. This means that the measurement can be repeated on the same nanowire and it will give the same conductance trace as long as the sample is kept under

Review on nanoparticles and nanostructured materials: history, sources, toxicity and regulations

• Jaison Jeevanandam,
• Ahmed Barhoum,
• Yen S. Chan,
• Alain Dufresne and
• Michael K. Danquah

Beilstein J. Nanotechnol. 2018, 9, 1050–1074, doi:10.3762/bjnano.9.98

Magnetic characterization of cobalt nanowires and square nanorings fabricated by focused electron beam induced deposition

• Federico Venturi,
• Gian Carlo Gazzadi,
• Amir H. Tavabi,
• Alberto Rota,
• Rafal E. Dunin-Borkowski and
• Stefano Frabboni

Beilstein J. Nanotechnol. 2018, 9, 1040–1049, doi:10.3762/bjnano.9.97

• magnetic sensing [5]. A new concept of fast memory, which is referred to as racetrack memory, has been proposed, based on the motion of domain walls along a nanowire (NW) subject to current pulses or external magnetic fields [6]. The strong research interest in such new types of memories is based on their

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

• properties [33]. In 2014, spin-coating was utilized to prepare ZnO nanowire arrays with tunable band gap, layered BiOBr–BiOI composites onto them. It showed that the BiOBr/BiOI composites played the role of sensitizer in the heterojunctions and were tunable by varying the BiOBr/BiOI ratio [34]. Kuang et al

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

• experiments. These advances accelerate the development of nanotechnology [20][21][22][23][24][25][26][27]. Recently, a breakthrough was achieved in research groups led by Kouwenhoven and Marcus. Both groups observed the integer ZBPs in a nanowire system [28]. These are the most persuading results so far

Review: Electrostatically actuated nanobeam-based nanoelectromechanical switches – materials solutions and operational conditions

• Liga Jasulaneca,
• Jelena Kosmaca,
• Raimonds Meija,
• Jana Andzane and
• Donats Erts

Beilstein J. Nanotechnol. 2018, 9, 271–300, doi:10.3762/bjnano.9.29

• a moving element (Ge nanowire) between two drain electrodes located symmetrically (Figure 1e,f drains 1 and 2) [14] and asymmetrically (Figure 1e,f drains 1 and 3) [11] relative to the switching element in 2T configuration was demonstrated. While switching between symmetrically located drain

• ] (Table 1). Thus, the contact area experiences higher current density than that inside the nanowire. This should be taken into account during analysis performed on NEM switch operation. The nanocontact area and stiffness of the switching element determine the on–off hysteresis width of a NEM switch. With

• width for a Mo6S3I6 nanowire bundle-based 2T NEM switch, when the Mo6S3I6 –Au contact area was reduced from 100 nm2 down to 45 nm2 while maintaining the same Von voltage. However, such reduction of the contact area results in an increase of the electrical current density flowing through it, which may

Dopant-stimulated growth of GaN nanotube-like nanostructures on Si(111) by molecular beam epitaxy

• Alexey D. Bolshakov,
• Alexey M. Mozharov,
• Georgiy A. Sapunov,
• Igor V. Shtrom,
• Nickolay V. Sibirev,
• Vladimir V. Fedorov,
• Evgeniy V. Ubyivovk,
• Maria Tchernycheva,
• George E. Cirlin and
• Ivan S. Mukhin

Beilstein J. Nanotechnol. 2018, 9, 146–154, doi:10.3762/bjnano.9.17

• atomic nitrogen flux. Nanowire formation The analysis of the SEM images (Figure 1a–f) and experimental data allows us to make several important conclusions. First, the cross-section of the synthesized NWs is hexagonal (see Figure 1f). Second, we registered the highest NW elongation rate value of 35.9 nm

• electron microscope (SEM) images of the nanowire (NW) arrays: a) image of the array grown on the substrate that underwent low temperature annealing (850 °C, sample 2); b) images of the array grown on the substrate that underwent high temperature annealing (1000 °C, sample 7); c) top view image of the

Combined scanning probe electronic and thermal characterization of an indium arsenide nanowire

• Tino Wagner,
• Fabian Menges,
• Heike Riel,
• Bernd Gotsmann and
• Andreas Stemmer

Beilstein J. Nanotechnol. 2018, 9, 129–136, doi:10.3762/bjnano.9.15

• spots may put limits on device integration. Therefore, being able to observe profiles of both electronic and thermal device properties at the nanoscale is important. Here, we show measurements by scanning thermal and Kelvin probe force microscopy of the same 60 nm diameter indium arsenide nanowire in

• operation. The observed temperature along the wire is substantially elevated near the contacts and deviates from the bell-shaped temperature profile one would expect from homogeneous heating. Voltage profiles acquired by Kelvin probe force microscopy not only allow us to determine the electrical nanowire

• conductivity, but also to identify and quantify sizable and non-linear contact resistances at the buried nanowire–electrode interfaces. Complementing these data with thermal measurements, we obtain a device model further permitting separate extraction of the local thermal nanowire and interface conductivities

Nematic topological defects positionally controlled by geometry and external fields

• Pavlo Kurioz,
• Marko Kralj,
• Bryce S. Murray,
• Charles Rosenblatt and
• Samo Kralj

Beilstein J. Nanotechnol. 2018, 9, 109–118, doi:10.3762/bjnano.9.13

• be exploited to form nanowire-type structures [9][13] consisting of NPs. In this contribution we study numerically the effects of geometry and an external electric field on the positions of nematic TDs using the Landau–de Gennes mesoscopic approach. Theoretical Background Of interest is the impact of

Beyond Moore’s technologies: operation principles of a superconductor alternative

• Igor I. Soloviev,
• Nikolay V. Klenov,
• Sergey V. Bakurskiy,
• Mikhail Yu. Kupriyanov,
• Alexander L. Gudkov and
• Anatoli S. Sidorenko

Beilstein J. Nanotechnol. 2017, 8, 2689–2710, doi:10.3762/bjnano.8.269

• in the middle to which the third terminal tip is connected. A current pulse from the third terminal switches off the superconductivity of the nanowire, that is similar to SFT operation to some extent. Unlike a Josephson junction, the nanowire in the resistive state possesses several kiloohms of

Direct writing of gold nanostructures with an electron beam: On the way to pure nanostructures by combining optimized deposition with oxygen-plasma treatment

• Domagoj Belić,
• Mostafa M. Shawrav,
• Emmerich Bertagnolli and
• Heinz D. Wanzenboeck

Beilstein J. Nanotechnol. 2017, 8, 2530–2543, doi:10.3762/bjnano.8.253

• recently utilized FEBID of Au to directly write metal-oxide-semiconductor capacitors [41] and to deposit Au nanocatalyst templates for Si nanowire syntheses [42]. The main issue which is hindering the widespread use of FEBID is the low Au content in the produced nanostructures: when using the common

Fabrication of CeO₂–MO_x (M = Cu, Co, Ni) composite yolk–shell nanospheres with enhanced catalytic properties for CO oxidation

• Ling Liu,
• Jingjing Shi,
• Hongxia Cao,
• Ruiyu Wang and
• Ziwu Liu

Beilstein J. Nanotechnol. 2017, 8, 2425–2437, doi:10.3762/bjnano.8.241

• interfacial oxidation–reduction under mild conditions. For example, Mn3O4/CeO2 hybrid nanotubes were created by a template-based process involving a redox reaction between the cryptomelane-type manganese oxide nanowire template and Ce(NO3)3 [20]. Ce–Mn nanotubes were also fabricated by treating Ce(OH)CO3

Comparing postdeposition reactions of electrons and radicals with Pt nanostructures created by focused electron beam induced deposition

• Julie A. Spencer,
• Michael Barclay,
• Miranda J. Gallagher,
• Robert Winkler,
• Ilyas Unlu,
• Yung-Chien Wu,
• Harald Plank,
• Lisa McElwee-White and
• D. Howard Fairbrother

Beilstein J. Nanotechnol. 2017, 8, 2410–2424, doi:10.3762/bjnano.8.240

• purification by LAEBID resulted not only in higher platinum content but also in an improved platinum coalescence and a transition from amorphous to graphitic carbon. The net effect of these chemical and structural transformations was a 100-fold improvement in nanowire resistivity, while maintaining a high

Substrate and Mg doping effects in GaAs nanowires

• Perumal Kannappan,
• Nabiha Ben Sedrine,
• Jennifer P. Teixeira,
• Maria R. Soares,
• Bruno P. Falcão,
• Maria R. Correia,
• Nestor Cifuentes,
• Emilson R. Viana,
• Marcus V. B. Moreira,
• Geraldo M. Ribeiro,
• Alfredo G. de Oliveira,
• Juan C. González and
• Joaquim P. Leitão

Beilstein J. Nanotechnol. 2017, 8, 2126–2138, doi:10.3762/bjnano.8.212

• structure, but when scaled down to the nanowire form, the occurrence of the wurtzite (WZ) crystalline phase is more prevalent due to a high surface-to-volume ratio and a low surface energy [10][11][12]. The WZ phase is more favorable for nanowires with small diameters, whereas for larger diameters, the ZB

• nanowires [11][12][13][14][15][16][17][18][19]. In addition to the intentional doping, the distribution of crystalline phases and defects (like stacking faults and twin planes) along the nanowire length depends on the interplay between various growth parameters, namely temperature, effective V/III ratio

• -n junctions in nanowire-based solar cells [5][6]. The control of the doping in GaAs is a fundamental issue. This is particularly true regarding the p-type doping if one intends to follow traditional architectures based on the use of n-type buffer layers, as is the case of thin film based solar cells

Synthesis and catalytic application of magnetic Co–Cu nanowires

• Lijuan Sun,
• Xiaoyu Li,
• Zhiqiang Xu,
• Kenan Xie and
• Li Liao

Beilstein J. Nanotechnol. 2017, 8, 1769–1773, doi:10.3762/bjnano.8.178

• difference between the Co–Cu nanowire synthesis with and without application of an external magnetic field. It was very evident that the linear structure of the Co–Cu nanowires prepared without an external magnetic field was undesirable. Moreover, the Co–Cu nanowires prepared without an external magnetic

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

• broken, indicating the conductance of the SiNR is almost comparable to a metallic nanowire. The resistance of a silicene field effect transistor (FET) is estimated to be about 40 kΩ from the drain current measured as a function of the drain voltage [24]. The sheet resistance of multilayer silicene sheets

Metal oxide nanostructures: preparation, characterization and functional applications as chemical sensors

• Dario Zappa,
• Angela Bertuna,
• Elisabetta Comini,
• Navpreet Kaur,
• Nicola Poli,
• Veronica Sberveglieri and
• Giorgio Sberveglieri

Beilstein J. Nanotechnol. 2017, 8, 1205–1217, doi:10.3762/bjnano.8.122

• Raman spectrum of WO3 nanowire networks. All identified peaks can be attributed to tungsten trioxide, while there is no sign of alumina (corundum) peaks related to the polycrystalline substrate. This means that tungsten oxide covers the entire substrates. More specifically, the peaks at 707 cm−1 and

• outperform the results reported in literature with similar morphologies. “Small sensor system” tests In order to study these materials in real applications, metal oxide nanowires have been integrated in an electronic nose called “Small Sensor System” (S3). Nanowire devices were integrated together with

• of the source material are continually provided, the material starts to condensate in the form of a solid precipitate. The 1D crystal growth begins, and it continues as long as the source material is supplied [51]. The nanowire growth was carried out in a custom-made tubular furnace [52]. The