Publications by authors named "Saurabh Karwal"

Majorana bound states are expected to appear in one-dimensional semiconductor-superconductor hybrid systems, provided they are homogeneous enough to host a global topological phase. In order to experimentally investigate the uniformity of the system, we study the spatial dependence of the local density of states in multiprobe devices where several local tunneling probes are positioned along a gate-defined wire in a two-dimensional electron gas. Spectroscopy at each probe reveals a hard induced gap and an absence of subgap states at zero magnetic field.

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Article Synopsis
  • * Researchers used plasma-enhanced ALD to grow large-area MoS and examined how high-κ dielectrics like HfO and AlO impact the electrical properties and doping of these transistors.
  • * Findings indicate that factors such as dielectric stoichiometry, carbon impurities, and surface oxidation significantly influence MoS FET performance, with the optimal setup involving thermal ALD AlO to minimize surface damage while enhancing dielectric characteristics.
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The small footprint of semiconductor qubits is favorable for scalable quantum computing. However, their size also makes them sensitive to their local environment and variations in the gate structure. Currently, each device requires tailored gate voltages to confine a single charge per quantum dot, clearly challenging scalability.

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Highly uniform quantum systems are essential for the practical implementation of scalable quantum processors. While quantum dot spin qubits based on semiconductor technology are a promising platform for large-scale quantum computing, their small size makes them particularly sensitive to their local environment. Here, we present a method to electrically obtain a high degree of uniformity in the intrinsic potential landscape using hysteretic shifts of the gate voltage characteristics.

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Topological superconductivity can be engineered in semiconductors with strong spin-orbit interaction coupled to a superconductor. Experimental advances in this field have often been triggered by the development of new hybrid material systems. Among these, two-dimensional electron gases (2DEGs) are of particular interest due to their inherent design flexibility and scalability.

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Oxygen is often detected as impurity in metal and metal nitride films prepared by atomic layer deposition (ALD) and its presence has profound and adverse effects on the material properties. In this work, we present the case study of HfN films prepared by plasma-assisted ALD by alternating exposures of CpHf(NMe) and H plasma. First, we identify the primary source of O contamination in the film.

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In this work, we present an extensive characterization of plasma-assisted atomic-layer-deposited SnO layers, with the aim of identifying key material properties of SnO to serve as an efficient electron transport layer in perovskite solar cells (PSCs). Electrically resistive SnO films are fabricated at 50 °C, while a SnO film with a low electrical resistivity of 1.8 × 10 Ω cm, a carrier density of 9.

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Low-temperature controllable synthesis of monolayer-to-multilayer thick MoS2 with tuneable morphology is demonstrated by using plasma enhanced atomic layer deposition (PEALD). The characteristic self-limiting ALD growth with a growth-per-cycle of 0.1 nm per cycle and digital thickness control down to a monolayer are observed with excellent wafer scale uniformity.

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Oxide and nitride thin-films of Ti, Hf, and Si serve numerous applications owing to the diverse range of their material properties. It is therefore imperative to have proper control over these properties during materials processing. Ion-surface interactions during plasma processing techniques can influence the properties of a growing film.

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Molecular layer deposition (MLD) was used to coat micron-sized protein particles in a fluidized bed reactor. Our results show that the dissolution rate of particles coated via MLD rapidly decreases with the increase in number of coating cycles, while the uncoated particles dissolve instantaneously.

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