Current-induced mechanical torque in chiral molecular rotors

• Richard Korytár and
• Ferdinand Evers

Beilstein J. Nanotechnol. 2023, 14, 711–721, doi:10.3762/bjnano.14.57

• unidirectional rotation in the STM setup requires a degree of symmetry breaking. There are two typical situations, that is, either the molecule by itself exhibits a handedness (chirality) or chirality is imposed by the geometry of the molecular junction [6][10]. The purpose of this article is to provide a

• linear response (under the threshold current). A small symmetry breaking is needed in order to discriminate between the three states. Quantum effects are responsible for a rich transport phenomenology of molecular junctions [20]. Here, we pause to discuss quantum effects related to the electronic degrees

Investigations on the optical forces from three mainstream optical resonances in all-dielectric nanostructure arrays

• Guangdong Wang and
• Zhanghua Han

Beilstein J. Nanotechnol. 2023, 14, 674–682, doi:10.3762/bjnano.14.53

• electromagnetic field enhancement. We should note that all these values in Table 1 are rough numbers with no optimization (e.g., the Q-factor of the quasi-BIC resonance can be controlled by the level of symmetry breaking (the size and position of the elliptical slot)). However, the results in Table 1 with

Observation of multiple bulk bound states in the continuum modes in a photonic crystal cavity

• Rui Chen,
• Yi Zheng,
• Xingyu Huang,
• Qiaoling Lin,
• Chaochao Ye,
• Meng Xiong,
• Martijn Wubs,
• Yungui Ma,
• Minhao Pu and
• Sanshui Xiao

Beilstein J. Nanotechnol. 2023, 14, 544–551, doi:10.3762/bjnano.14.45

• of the incident field away from the Г point, a small extent of symmetry breaking occurs and the Q factor decreases, as shown in Figure 1c. The Q factor discussed above is the radiative Q factor (Qr), which only depends on the ideal mode radiation loss. The Q factor of any realistic device is

Upper critical magnetic field in NbRe and NbReN micrometric strips

• Zahra Makhdoumi Kakhaki,
• Antonio Leo,
• Federico Chianese,
• Loredana Parlato,
• Giovanni Piero Pepe,
• Angela Nigro,
• Carla Cirillo and
• Carmine Attanasio

Beilstein J. Nanotechnol. 2023, 14, 45–51, doi:10.3762/bjnano.14.5

• 0.13 ≤ x ≤ 0.38 crystallizes in the non-centrosymmetric Ti5Re24-type structure with the space group (No. 217) [9][10][11][12]. This non-centrosymmetric nature of the material leads to intriguing and unconventional physical properties such as the time-reversal symmetry breaking observed with muon-spin

Impact of electron–phonon coupling on electron transport through T-shaped arrangements of quantum dots in the Kondo regime

• Patryk Florków and
• Stanisław Lipiński

Beilstein J. Nanotechnol. 2021, 12, 1209–1225, doi:10.3762/bjnano.12.89

• - and interdot interactions [93]. Similarly, one can also expect the same CO ground state with (2,0) or (0,2) states for the DTQD. The SBMFA formalism we use (Equation 2 and Equation 12) with no symmetry breaking perturbation does not point directly to CO as the ground state. Instead we found a

• infinite time of transition from one degenerate state into another (z = 0). We have obtained clear evidence of a charge-ordered ground state in n = 2 domain within the SBMFA formalism by adding a small symmetry breaking term to the Hamiltonian in Equation 2. Similarly, as has been proposed in [94], we have

• temperature is TK ≈ 10−9. Due to numerical uncertainty in the immediate vicinity of λCK the conductance and occupation lines presented on Figure 11a are drawn by dashed lines. The transition to this charge Kondo state, together with the examination of its stability under symmetry breaking perturbations, is

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

• depend on the direction [44]. The consequence of symmetry breaking is a shift of the Dirac points in the reciprocal lattice away from the K and K’ points. The broken symmetry also enhances the intrinsic spin–orbit (SO) coupling in carbon nanotubes compared with flat graphene. Apart from curvature [44][45

Optically and electrically driven nanoantennas

• Monika Fleischer,
• Dai Zhang and
• Alfred J. Meixner

Beilstein J. Nanotechnol. 2020, 11, 1542–1545, doi:10.3762/bjnano.11.136

• -power excitation of nanoantennas, higher order contributions to the particle polarization are no longer negligible, and nonlinear effects become apparent. Due to their inherent symmetry breaking, nanoantennas can act as local sources of second harmonic generation (SHG) with attractive applications in

Interfacial charge transfer processes in 2D and 3D semiconducting hybrid perovskites: azobenzene as photoswitchable ligand

• Nicole Fillafer,
• Tobias Seewald,
• Lukas Schmidt-Mende and
• Sebastian Polarz

Beilstein J. Nanotechnol. 2020, 11, 466–479, doi:10.3762/bjnano.11.38

• conformational change and the associated symmetry breaking makes the transition S0→S1 more likely for the cis-isomer. By irradiating a solution of the ligands in an appropriate solvent at 313 nm (3.96 eV) the photoswitching can be observed via UV–vis absorption spectroscopy (see Figure 1). In the following, we

Multiple Fano resonances with flexible tunablity based on symmetry-breaking resonators

• Xiao bin Ren,
• Kun Ren,
• Ying Zhang,
• Cheng guo Ming and
• Qun Han

Beilstein J. Nanotechnol. 2019, 10, 2459–2467, doi:10.3762/bjnano.10.236

• 300072, China 10.3762/bjnano.10.236 Abstract A symmetry-breaking nanostructure is proposed to achieve multiple Fano resonances. The nanostructure consists of an asymmetric ring resonator coupled to a plasmonic waveguide. The broken symmetry is introduced by deviating the centers of regular ring. New

• new opportunities to design on-chip optical devices with great tuning performance. Keywords: multiple Fano resonance; off-centered ring resonators; plasmonic waveguide; surface plasmon polaritons; symmetry-breaking; tunable resonance; Introduction Fano resonances originate from the interference of a

• Fano peaks appear in the transmission spectrum after combining two symmetry-breaking cavities with different dimensions. Structure and Theory Figure 1 shows the schematic diagram of the MDM waveguide–cavity coupled system. The inset is the 3D view. The asymmetric cavity that we designed is an off

Features and advantages of flexible silicon nanowires for SERS applications

• Hrvoje Gebavi,
• Vlatko Gašparić,
• Dubravko Risović,
• Nikola Baran,
• Paweł Henryk Albrycht and
• Mile Ivanda

Beilstein J. Nanotechnol. 2019, 10, 725–734, doi:10.3762/bjnano.10.72

• weak metal affinity was facilitated through the surface immobilization via 4-MPBA [30][31]. The 4-MPBA reporter features are predominantly based on re-orientation i.e. binding of the analyte via the boronic acid group causing a symmetry breaking and activation of the charge transfer mechanism which

Improving the catalytic activity for hydrogen evolution of monolayered SnSe_2(1−x)S_2x by mechanical strain

• Sha Dong and
• Zhiguo Wang

Beilstein J. Nanotechnol. 2018, 9, 1820–1827, doi:10.3762/bjnano.9.173

• hexagonal site, and the top of S/Se atoms. Because of the symmetry breaking in SnSe2(1−x)S2x monolayers, the number of possible adsorption sites is increased. For example, there are six adsorption sites for hydrogen on the SnSeS monolayer, as shown in Figure 2, i.e., the top of S (TS) and Se (TSe) atoms

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

• to a single superconductor (i.e., in the absence of superconducting phase differences) was discussed in [29]. Here, we summarize the main results, as revealed by the simplified tight-binding model given by Equation 1. First, we consider a triangular system without a symmetry-breaking potential, Veff

• represent topologically nontrivial phases with = −1. The effect of a symmetry-breaking potential is illustrated in panel (B) of Figure 2. While the topology of the phase diagram is the same, the phase boundaries are modified significantly with respect to panel (A). We note that this result was obtained by

• applying a rather modest symmetry breaking potential with values Veff = (0.67, 0.17, −0.33, −0.33, −0.33, 0.17) meV on the six chains. To get further insight into the nature of the phases shown in Figure 2, we calculate the minimum quasiparticle energy Emin(μ,ΓB) along the constant chemical potential cuts

Robust midgap states in band-inverted junctions under electric and magnetic fields

• Álvaro Díaz-Fernández,
• Natalia del Valle and
• Francisco Domínguez-Adame

Beilstein J. Nanotechnol. 2018, 9, 1405–1413, doi:10.3762/bjnano.9.133

• crystalline insulator states in Pb1−xSnxSe [9]. High-resolution scanning tunneling microscopy studies of these topological crystalline insulators provided strong evidence of the coexistence of massless Dirac fermions, protected by crystal symmetry, with massive Dirac fermions consistent with crystal-symmetry

• breaking [10]. Recently, these results have received further support with the aid of Dirac Landau level spectroscopy [11][12]. Band-inverted structures were already studied back in the 1980’s and 1990’s under the name of band-inverted junctions, in which the fundamental gap has opposite sign on each

Valley-selective directional emission from a transition-metal dichalcogenide monolayer mediated by a plasmonic nanoantenna

• Haitao Chen,
• Mingkai Liu,
• Lei Xu and
• Dragomir N. Neshev

Beilstein J. Nanotechnol. 2018, 9, 780–788, doi:10.3762/bjnano.9.71

• 10.3762/bjnano.9.71 Abstract Background: Two-dimensional (2D) transition-metal dichalcogenides (TMDCs) with intrinsically crystal inversion-symmetry breaking have shown many advanced optical properties. In particular, the valley polarization in 2D TMDCs that can be addressed optically has inspired new

• polarization; Introduction The inversion-symmetry breaking and quantum confinement in monolayer TMDCs offer unprecedented opportunities to explore valley-based physics and applications [1][2][3]. The valley pseudospin is associated with the degenerate energy extrema in momentum space [3]. In monolayer TMDCs

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

• components [10]: an amplitude (also referred to as a hydrodynamic) field, and a symmetry breaking (also referred to as a gauge or nonhydrodynamic) field. If the characteristic size of a nanoparticle is comparable to the amplitude correlation length of an order parameter (which roughly estimates the core size

• of a defect), and if the nanoparticle does not sufficiently disturb the symmetry breaking field surrounding the core of the defect, then the defect could efficiently trap the NP due to the defect core displacement (DCR) mechanism [11]. In this case, a relatively energetically expensive defect core

Fluorination of vertically aligned carbon nanotubes: from CF₄ plasma chemistry to surface functionalization

• Claudia Struzzi,
• Mattia Scardamaglia,
• Jean-François Colomer,
• Alberto Verdini,
• Luca Floreano,
• Rony Snyders and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2017, 8, 1723–1733, doi:10.3762/bjnano.8.173

• −1) is activated after the conversion of the sp2 coordinated carbon lattice into sp3 hybridized system as a consequence of the symmetry-breaking introduced by the functionalization and by the defects [34][35]. The intensity (I) and the area (A) ratios of the D and G modes (D/G) are extracted by curve

Nitrogen-doped twisted graphene grown on copper by atmospheric pressure CVD from a decane precursor

• Ivan V. Komissarov,
• Nikolai G. Kovalchuk,
• Vladimir A. Labunov,
• Ksenia V. Girel,
• Olga V. Korolik,
• Mikhail S. Tivanov,
• Algirdas Lazauskas,
• Mindaugas Andrulevičius,
• Tomas Tamulevičius,
• Viktoras Grigaliūnas,
• Šarunas Meškinis,
• Sigitas Tamulevičius and
• Serghej L. Prischepa

Beilstein J. Nanotechnol. 2017, 8, 145–158, doi:10.3762/bjnano.8.15

• the laser Elaser ≈ 2.33 eV, we get n ≈ 2.2 × 1011 cm−2. The reason for lower defect density as compared to the nN value may be the following. The nitrogen atoms could be located in such a configuration that almost does not affect the ID value. In particular, the pyrrolic nitrogen due to the symmetry

• breaking of hexagon rings should have a strong impact on the intensity of the D band and cannot be considered as the main type of defect in the studied films. Twisted graphene Now we focus on the Raman data associated with the double layer graphene. In Figure 11a we plot selected spectra associated with

Plasma fluorination of vertically aligned carbon nanotubes: functionalization and thermal stability

• Claudia Struzzi,
• Mattia Scardamaglia,
• Axel Hemberg,
• Luca Petaccia,
• Jean-François Colomer,
• Rony Snyders and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2015, 6, 2263–2271, doi:10.3762/bjnano.6.232

• symmetry-breaking defects or damage of the lattice [52]. In Figure 4, the pristine sample already shows a high intensity D-peak when compared to the plasma-fluorinated nanotubes. This is because of the sp3 behavior and intrinsic defects revealed particularly when acquiring the Raman spectrum from a region

Two-phase equilibrium states in individual Cu–Ni nanoparticles: size, depletion and hysteresis effects

• Aram S. Shirinyan

Beilstein J. Nanotechnol. 2015, 6, 1811–1820, doi:10.3762/bjnano.6.185

• forth and back loops are different (Figure 5) representing the symmetry breaking effect. The increasing of the sizes leads to the vanishing of hysteresis effect. Size-dependent solubility diagram Next we consider only the solubility curves on T–X diagram yielding the size-dependent solubility diagram

• . The increasing of the sizes leads to the vanishing of the hysteresis effect. Qualitative representation of size-dependent solubility diagrams for solid–liquid transformation in the isolated Cu–Ni nanoparticle and phase transition symmetry breaking effect shown by the intersection of nanosolidus and

Enhanced fullerene–Au(111) coupling in (2√3 × 2√3)R30° superstructures with intermolecular interactions

• Michael Paßens,
• Rainer Waser and
• Silvia Karthäuser

Beilstein J. Nanotechnol. 2015, 6, 1421–1431, doi:10.3762/bjnano.6.147

• bond in combination with Au adatoms. Most interestingly, a symmetry breaking is observed in this u-R30° structure due to the adsorption of C60 molecules with the 5:6 C–C bond (with one mirror plane as symmetry element) on a surface position with a C3-axis as symmetry element. With respect to the C60

• the Fermi energy of the metal, like observed here. Furthermore, a newly created adatom–C60 unit may be polar and therefore, would give rise to intermolecular dipol–dipol interactions. These polar interactions in combination with the symmetry breaking are assumed to result in the formation of a polar

• adatoms. The observed symmetry breaking causes the lifting of the degeneracy of the LUMO and LUMO+1 orbitals in the differential conductance spectra. In addition, hybrid fullerene–metal states are identified and attributed to partly covalent interactions between adatoms on the Au(111) surface and C60

Nanoparticle shapes by using Wulff constructions and first-principles calculations

• Georgios D. Barmparis,
• Zbigniew Lodziana,
• Nuria Lopez and
• Ioannis N. Remediakis

Beilstein J. Nanotechnol. 2015, 6, 361–368, doi:10.3762/bjnano.6.35

• , experimentally it has been found that objects such as nanorods can be systematically produced with an adequate selection of the solution growth. In that case the symmetry breaking appears very early in the formation of the seed as then some of the facets (but not all those equivalent by symmetry) can be blocked

Quasi-1D physics in metal-organic frameworks: MIL-47(V) from first principles

• Danny E. P. Vanpoucke,
• Jan W. Jaeken,
• Stijn De Baerdemacker,
• Kurt Lejaeghere and
• Veronique Van Speybroeck

Beilstein J. Nanotechnol. 2014, 5, 1738–1748, doi:10.3762/bjnano.5.184

• MIL-47(V) structure is the symmetry breaking in the V-chain. Whereas for the as-synthesized version all V atoms are positioned on a straight line, the V atoms exhibit a zig-zag configuration in the b–c-plane of the calculated structure. Although the separation in the b-direction (bVV) is rather small

• in absolute value (cf. Table 2), the resulting improvement in energy due to this symmetry breaking is about 300 meV for the 72-atom unit cell used. A more detailed investigation of the crystal geometry, presented in Table 2, shows that the vanadium–oxygen chains present almost identical bond lengths

Sublattice asymmetry of impurity doping in graphene: A review

• James A. Lawlor and
• Mauro S. Ferreira

Beilstein J. Nanotechnol. 2014, 5, 1210–1217, doi:10.3762/bjnano.5.133

• segregation effect It is clear that any degree of asymmetry between the two equivalent sublattices is the result of a symmetry breaking operation. Current theoretical attempts to explain the sublattice asymmetry in the nitrogen doping seen in the experiments discussed in the previous section suggest that the

• effect comes from either the energetically preferable positioning of nitrogen on the graphene edge during the growth process [41][42], where the symmetry breaking effect is the edge structure, or from inter-impurity interactions in the impurity ensemble [39][43] where the symmetry is broken by the

• that the electrons in the former kind of device will be subjected to less scattering leading to an increase in the quantum conductance, closer to that of the pristine system when subjected to a positive bias. It should also be noted that that symmetry breaking in nanoribbons occurs via edge effects and

Dye-doped spheres with plasmonic semi-shells: Lasing modes and scattering at realistic gain levels

• Nikita Arnold,
• Boyang Ding,
• Calin Hrelescu and
• Thomas A. Klar

Beilstein J. Nanotechnol. 2013, 4, 974–987, doi:10.3762/bjnano.4.110

• -shell modes by slowly opening the closed shell. Labeling is hence carried out by using the multipolar and azimuthal numbers (l,m) [7][11]. While in a spherically symmetric shell, each multipolar mode is (2l+1) times degenerate, the symmetry breaking that is introduced by opening a hole in the shell not

• this experimental study were, however, fully spherically symmetric. Very recently, it has been proposed that symmetry breaking might have advantages because a low gain threshold is required [50] and the coherent emission becomes directional [51]. In both theoretical papers, a geometry was assumed, in