a Qubit heterostructure schematic. The inset dashed rectangle depicts alloy and roughness disorder near interfaces. b An energy, E, diagram indicating that a quantum well forms in the s-Si layer owing to conduction band edge offset from adjacent SiGe layers, and the confinement potential width, w, is shaped by growth roughness and intermixing length, L. Generally, interface roughness is not strictly correlated between interfaces and intermixing may be superposed to yield c complex 3D interface structures that are intractable for d the highest spatial resolution post-growth measurement techniques, such as transmission electron microscopy (TEM) and APT owing to, e.g., limited practical measurement volumes smaller than established roughness correlation lengths, along with probe convolution effects, e.g., averaging of structure information along the TEM beam path through a cross-sectional slice. Here, 4τ denotes the observed interface width including various disorder contributions. Image and caption from https://doi.org/10.1038/s41534-024-00827-8

🧪 ⚛️ neat result from Sandia/CINT and EAG using multiscale, multiperspective STM, MBE, and STEM to study interfacial disorder at Si/SiGe quantum well interfaces to predict, with effective mass theory, confinement potential variation for semiconductor qubits doi.org/10.1038/s415... #SurfSci

Suppression of Midinfrared Plasma Resonance Due to Quantum Confinement in $\ensuremath{\delta}$-Doped Silicon The classical Drude model provides an accurate description of the plasma resonance of three-dimensional materials, but only partially explains two-dimensional systems where quantum mechanical effects ...

⚛️ 🧪 we were surprised by the lack of plasma resonance in our highly doped P delta layers in Si, so we developed a model to explain it and a framework to design 2D systems with suppressed plasma resonance #semiconductor #SurfSci doi.org/10.1103/Phys...

Scanning tunneling microscope image of an InAs surface exposed to about 0.1 monopolies of Sb showing that Sb unexpectedly digs into the surface to form a c(4x4) reconstruction, meaning it intermixes more strongly with InAs than previously thought, which impacts how abruptly interfaces can be grown for device applications. From https://doi.org/10.1063/1.4976682

⚛️ 🧪#TBT here we used MBE, STM, and DFT (experiment + theory) to study the atomic structure of InAs surfaces and were surprised that Sb digs into the surface, which impacts growing IR sensors with abrupt interfaces doi.org/10.1063/1.49...
#SurfSci #Semiconductor

⚛️ 🧪 here we used vapor hydrofluoric acid (HF) to remove the oxide from Si and SiGe more cleanly than by dipping in liquid HF and recrystallized the surface at 600 C, low enough for CMOS integration or to preserve SiGe quantum wells for qubits doi.org/10.1021/acs.... #semiconductor #SurfSci

Left: scanning tunneling microscope (STM) image of an InSb (001) surface after exposing 1 ML of In to Sb at 395 C with regions of c(4x4) reconstruction circled within the typical c(2x6) reconstruction. Middle: reflection high energy electron diffraction (RHEED) patterns showing the 1x3 surface symmetry is dominant. Right: surface reconstruction phase diagram for As and Sb on the InSb surface generated by density functional theory (DFT). From https://doi.org/10.1016/j.susc.2017.09.014

⚛️ 🧪 #TBT sometimes you learn more from computation + experiment than either alone. Here we used STM, MBE, and DFT to explore atomic arrangements on InSb with insights into how Sb and As intermixing can impact alloys and superlattices for IR detectors doi.org/10.1016/j.su... #SurfSci #semiconductor

Schematics illustrating the possibilities for new materials and devices through atomic precision advanced manufacturing. Center: diagram of atomic desorption lithography with an STM and selective gas-phase ultrahigh doping. Top: electronics from integrating APAM doping into CMOS: energy efficient digital electronics (e.g. TFETs), analog sensors, and superconductivity. Bottom left: optoelectronics from incorporating new precursor gases and atomic ordering: LEDs and quantum optics. Bottom right: overlap between APAM electronics and optoelectronics for quantum computing. From section 5.6 of https://doi.org/10.1088/2399-1984/ada901

⚛️ 🧪 Atomic scale interactions matter as #semiconductor device dimensions reach countable numbers of atoms. This lays out the challenges, opportunities, and recent advances to scale up manufacturing atomically precise devices for transistors, qubits, and new materials #SurfSci doi.org/10.1088/2399...

We just found 10 surface scientists @🦋 #SciSky 🎉 Help us find more! #UHV #STM #XPS #UPS #ARPES #AFM #ChemPhys #PhySky #ChemSky #SurfSci #SurfaceScience
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