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

• features are observed in recent experiments on the detection of Majoranas and could thus help to properly characterize them. Keywords: hybrid superconductor–semiconductor nanowires; interactions; Majorana bound states; quantum dots; Introduction Semiconducting nanowires with strong spin–orbit interaction

• , such as InAs or InSb, are becoming ideal systems for the artificial generation of topological superconductivity [1][2][3]. In addition to its fundamental interest, such nanowires that may host Majorana bound states (MBSs) at their ends or interfaces [4][5] constitute promising platforms for Majorana

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

• temperatures. Keywords: Josephson effect; Josephson junctions; quantum dots; superconducting quantum dots; topological states; topological superconductors; Introduction Since the discovery of the quantum Hall effect [1][2] and the theoretical prediction of Majorana bound states in triplet superconductors [3

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

• superconductors (TSs) is being vigorously explored at present. After Kitaev [1] showed that a one-dimensional (1D) spinless fermionic lattice model with nearest-neighbor p-wave pairing (‘Kitaev chain’) features a topologically nontrivial phase with Majorana bound states (MBSs) at open boundaries, references [2][3

Spatial Rabi oscillations between Majorana bound states and quantum dots

• Jun-Hui Zheng,
• Dao-Xin Yao and
• Zhi Wang

Beilstein J. Nanotechnol. 2018, 9, 1527–1535, doi:10.3762/bjnano.9.143

• of this amplitude equality by analyzing the spatial Rabi oscillations of the quantum states of a quantum dot that is tunneling-coupled to the Majorana bound states. Results: We find two resonant Rabi driving energies that correspond to the energy splitting due to the coupling of two spatially

• separated Majorana bound states. The resulting Rabi oscillating frequencies from these two different resonant driving energies are identical for the Majorana bound states, while different for ordinary Andreev bound states. We further study a double-quantum-dot setup and find a nonlocal quantum correlation

• between them that is mediated by two Majorana bound states. This nonlocal correlation has the signature of additional resonant driving energies. Conclusion: Our method can be used to distinguish between Majorana bound states and Andreev bound states. It also gives a precise measurement of the energy

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

• produced in a charge transport measurement by tunneling electrons between the semiconductor wire and external electrodes attached to its ends [14][15][16][17][18][19][20][21][22][23][24]. These experiments have provided strong indications regarding the presence of Majorana bound states at the end of the

• sign change of the Pfaffian, is accompanied by the closing of the quasiparticle gap at k = 0. Results and Discussion Nanowire coupled to superconductors with no relative phase difference The emergence of topological superconductivity and zero-energy Majorana bound states in core–shell nanowires coupled

• system with two pairs of Majorana bound states (on chains 2 and 3). We also note that the low-field phase boundaries converge to a single boundary in the limit of isolated chains, i.e., when the inter-chain hopping energy is much smaller than the hopping along the chains, t′/t → 0. In this case three

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

• with Majorana bound states (MBSs). The conductance and the noise Fano factor are calculated based on a tight-binding model by adopting a non-equilibrium Green’s function method. It is found that the disorder can effectively lead to a reduction in the conductance peak spacings and significantly suppress

• conductance; Introduction Searching for Majorana bound states (MBSs) have recently received widespread attention due to their potential applications in topologically-protected quantum computing [1][2][3][4][5][6][7][8][9]. In the past two decades, the realizations of MBSs has been predicted in many condensed

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

• –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

• Madrid, E-28049 Madrid, Spain Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC), Cantoblanco, 28049 Madrid, Spain 10.3762/bjnano.9.127 Abstract Hybrid superconductor–semiconductor nanowires with Rashba spin–orbit coupling are arguably becoming the leading platform for the search of Majorana bound

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

• gases that are strongly coupled to thin superconducting layers, as well as probing possible topological phases supporting Majorana bound states in such setups. We show that a large band shift is induced in the semiconductor by the superconductor in this geometry, thus making it challenging to realize a

• . Keywords: Majorana fermions; mesoscopic physics; proximity effect; quantum computing; topological superconductivity; Introduction Topological superconductors host zero-energy Majorana bound states at their edges that are highly sought for applications in topological quantum computing [1][2][3]. The two

• proposals to realize topological superconductivity that have received the most attention to date involve engineering Majorana bound states in either low-dimensional semiconducting systems [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] or in ferromagnetic atomic chains [24][25][26