Related papers: Superconductivity in hyperdoped Ge by molecular be…
Large area epitaxy of two-dimensional (2D) layered materials with high material quality is a crucial step in realizing novel device applications based on 2D materials. In this work, we report high-quality, crystalline, large-area gallium…
The in-situ growth of superconducting MgB2 thin films was examined from various perspectives. The paper discusses (1) growth temperature, (2) the effect of excess Mg, (3) the effect of residual gas during growth, (4) the effect of in-situ…
Superconducting properties of thin films can be vastly different from those of bulk materials. Seminal work has shown the critical temperature Tc of elemental superconductors decreases with decreasing film thickness when the normal-state…
Topological insulators possess a non-conductive bulk and present surface states, henceforth, they are electrically conductive along their boundaries. Bismuth selenide ($Bi_2Se_3$) is one of the most promising topological insulators.…
Superconducting epitaxial FeSe0.5Te0.5 thin films were prepared on SrTiO3 (001) substrates by pulsed laser deposition. The high purity of the phase, the quality of the growth and the epitaxy were studied with different experimental…
The III-Se layered semiconductors, including InSe and GaSe, are promising optoelectronic materials due to their relatively high electron mobilities at room temperature, nonlinear optical responses, ferroelectricity, self-passivated van der…
High-pressure studies on elements play an essential role in superconductivity research, with implications for both fundamental science and applications. Here we report the experimental discovery of surprisingly low pressure driving a novel…
(001)-oriented thin films of the three-dimensional Dirac semimetal cadmium arsenide can realize a quantum spin Hall insulator and other kinds of topological physics, all within the flexible architecture of epitaxial heterostructures. Here,…
GaMnAs thin films with different Mn doping concentrations were grown via molecular beam epitaxy using a substrate temperature of 250 {\deg}C. The thin films were investigated using photoluminescence (PL) measurements from 8 to 300 K.…
In FeSe-derived superconductors, the lack of a systematic and clean control on the carrier concentration prevents the comprehensive understanding on the phase diagram and the interplay between different phases. Here by K dosing and angle…
Microstructura lly clean, isov alently P-doped BaFe2As2 (Ba-122) single crystalline thin films have been prepared on MgO (001) substrates by molecular beam epitaxy. These films show a superconducting transition temperature (Tc) of over 30 K…
The presumably unconventional superconductor Beta-FeSe was deposited by radio frequency sputtering and molecular beam epitaxy (MBE) from two elementary sources. Superconducting thin films were grown in (001)-orientation on MgO(100) and…
Thin films of Fe(1+delta)Se(1-x)Te(x) (delta ~ 0.18 & x ~ 0.5) have been successfully grown on (100) oriented single crystalline SrTiO3 and LaAlO3 substrates by pulsed laser deposition. The crystal structure was characterized by x-ray…
Epitaxial Fe(Te,Se) thin films have been grown on various substrates but never been realized on magnetic layers. Here we report the epitaxial growth of four-fold Fe(Te,Se) film on a six-fold antiferromagnetic insulator, MnTe. The…
In this thesis, we have studied the evolution of superconductivity in amorphous Molybdenum Germanium ($\textit{a}$-MoGe) thin films. The work can be broken down into two parts. In the first part, we investigate the effect of decreasing…
We report different growth modes and corresponding magnetic properties of thin EuSe films grown by molecular beam epitaxy on BaF2, Pb1-xEuxSe, GaAs, and Bi2Se3 substrates. We show that EuSe growth predominantly in (001) orientation on…
We report the growth of high-quality GaN epitaxial thin films on graphene-coated c-sapphire substrates using pulsed-mode metalorganic vapor-phase epitaxy, together with the fabrication of freestanding GaN films by simple mechanical…
The co-integration of spin, superconducting, and topological systems is emerging as an exciting pathway for scalable and high-fidelity quantum information technology. High-mobility planar germanium is a front-runner semiconductor for…
Superconductivity was recently found in the simple tetragonal FeSe structure. Recent studies suggest that FeSe is unconventional, with the symmetry of the superconducting pairing state still under debate. To tackle these problems, clean…
We present a study of germanium as n-type dopant in wurtzite GaN films grown by plasma-assisted molecular beam epitaxy, reaching carrier concentrations of up to 6.7E20 cm-3 at 300K, well beyond the Mott density. The Ge concentration and…