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We describe the generation of entangling gates on superconductor-semiconductor hybrid qubits by ac voltage modulation of the Josephson energy. Our numerical simulations demonstrate that the unitary error can be below 10−5 in a variety of 75-ns-long two-qubit gates (CZ, 𝑖⁢SWAP, and √𝑖⁢SWAP) implemented using parametric resonance. We analyze the conditional 𝑍⁢𝑍 phase and demonstrate that the CZ gate needs no further phase-correction steps, while the 𝑍⁢𝑍 phase error in swap-type gates can be compensated by choosing pulse parameters. With decoherence considered, we estimate that qubit relaxation time needs to exceed 70μ⁢s to achieve the 99.9% fidelity threshold. 

The advancement of graphene has created a need in exploring its properties for different applications. One way to explore its properties is by reducing its hydrophobicity. To overcome hydrophobicity of graphene, surfactants have been used in functionalization, hence improving the surface properties of the graphene monolayer. Therefore, investigating surfactant treatment for CVD graphene becomes useful in understanding the surface property effects on graphene. This study utilizes CVD graphene on silicon substrates. Its treatment was done with varying concentrations of Sodium Cholate (SC) for different treatment times. These samples were then characterized using Atomic Force Microscopy (AFM) to investigate the surface properties of the samples before and after treatment. To be optimized, the graphene must remain attached to the silicon substrate. The result shows that the integrity of the graphene, which is basically the sp2 structure, is preserved as there was no delamination from the substrate even after treatment for as long as 2 hours in 1% weight/volume concentration of the SC solution. 

We synthesized single crystals for Mn2-xZnxSb (0 ≤ x ≤ 1) and studied their magnetic and electronic transport properties. This material system displays rich magnetic phase tunable with temperature and Zn composition. In addition, two groups of distinct magnetic and electronic properties, separated by a critical Zn composition of x = 0.6, are discovered. The Zn-less samples are metallic and characterized by a resistivity jump at the magnetic ordering temperature, while the Zn-rich samples lose metallicity and show a metal-to-insulator transition-like feature tunable by magnetic field. Our findings establish Mn2-xZnxSb as a promising material platform that offers opportunities to study how the coupling of spin, charge, and lattice degrees of freedom governs interesting transport properties in 2D magnets, which is currently a topic of broad interest. 

Plasmon coupling and hybridization in 2D materials plays a significant role for controlling light–matter interaction at the nanoscale. We present a near-field radiation heat transfer (NFRHT) between vertically separated graphene and black phosphorene sheets at different temperatures in nanoscale separations. Radiation exchange from the theory of fluctuation electrodynamics is modulated by the carrier density of graphene and phosphorene. Direct comparison of NFRHT black phosphorene–graphene to symmetric graphene–graphene radiation exchange can be as much as 4 times higher for the selected doping range in both armchair (AC) and zigzag (ZZ) orientations of BP. The strong NFRHT enhancement of the specific optical properties of the heterogenous 2D material is due to the strong coupling of propagating surface plasmon polaritons as demonstrated by the distribution of the heat transfer coefficient. We also demonstrate that the magnitude of the near-field radiation enhancement is found to acutely depend on the vacuum gap of the graphene and BP pair. Interestingly, for separation distances below 200 nm, the total near-field heat transfer between black phosphorene and graphene exceeds that between graphene and graphene by 5 times. The radiation enhancement can be further tuned based on the orientation, AC, and ZZ of black phosphorene. These results prominently enable dynamic control of the total NFRHT relying on tunable anisotropic characteristics of BP irrespective of graphene's optical conductivity. Furthermore, the heterogeneous pairs of 2D materials potentially provide alternative platforms to achieve beyond super-Planckian radiation. 

Strained trigonal Te has been predicted to host Weyl nodes supported by a non-symmorphic chiral symmetry. Using low-pressure physical vapor deposition, we systematically explored the growth of trigonal Te nanowires with naturally occurring strain caused by curvature of the wires. Raman spectra and high mobility electronic transport attest to the highly crystalline nature of the wires. Comparison of Raman spectra for both straight and curved nanowires indicates a breathing mode that is significantly broader and shifted in frequency for the curved wires. Strain induced by curvature during growth therefore may provide a simple pathway to investigate topological phases in trigonal Te.