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Hyong Min Kim

Publications and source records attributed to Hyong Min Kim.

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Deterministic patterning and alignment of tellurium quantum wires using nanoscale templates

Tellurium (Te) is an intriguing one-dimensional (1D) semiconductor that has recently attracted considerable interest as a p-type channel material. However, scalable synthesis methods have lacked control over the orientation and patterning of the Te atomic chains, thus limiting its practical use. Guided by theory, we overcome this challenge using nanowire-shaped templates to achieve oriented, single-crystal growth of Te on amorphous substrates. Strong alignment of Te atomic chains is achieved as template widths are reduced to sub-20 nm. This high structural order, confirmed by 4D scanning transmission electron microscopy, enables the observation of pristine quantum transport phenomena for deterministically patterned Te. Field-effect transistors exhibit well-defined conductance plateaus at 77 K due to population of individual 1D subbands. Furthermore, Coulomb blockade emerges at 1.7 K, with the Te channel acting as a gate-tunable quantum dot. This synthesis approach provides a scalable pathway for integration of Te-based quantum materials for future electronic and quantum technologies.

cond-mat.mtrl-sci

High Density, Localized Quantum Emitters in Strained 2D Semiconductors

Two-dimensional chalcogenide semiconductors have recently emerged as a host material for quantum emitters of single photons. While several reports on defect and strain-induced single photon emission from 2D chalcogenides exist, a bottom-up, lithography-free approach to producing a high density of emitters remains elusive. Further, the physical properties of quantum emission in the case of strained 2D semiconductors are far from being understood. Here, we demonstrate a bottom-up, scalable, and lithography-free approach to creating large areas of localized emitters with high density (~150 emitters/um2) in a WSe2 monolayer. We induce strain inside the WSe2 monolayer with high spatial density by conformally placing the WSe2 monolayer over a uniform array of Pt nanoparticles with a size of 10 nm. Cryogenic, time-resolved, and gate-tunable luminescence measurements combined with near-field luminescence spectroscopy suggest the formation of localized states in strained regions that emit single photons with a high spatial density. Our approach of using a metal nanoparticle array to generate a high density of strained quantum emitters opens a new path towards scalable, tunable, and versatile quantum light sources.

cond-mat.mes-hall

Scalable CMOS-BEOL compatible AlScN/2D Channel FE-FETs

Intimate integration of memory devices with logic transistors is a frontier challenge in computer hardware. This integration is essential for augmenting computational power concurrently with enhanced energy efficiency in big-data applications such as artificial intelligence. Despite decades of efforts, reliable, compact, energy efficient and scalable memory devices are elusive. Ferroelectric Field Effect Transistors (FE-FETs) are a promising candidate but their scalability and performance in a back-end-of-line (BEOL) process remain unattained. Here, we present scalable BEOL compatible FE-FETs using two-dimensional (2D) MoS2 channel and AlScN ferroelectric dielectric. We have fabricated a large array of FE-FETs with memory windows larger than 7.8 V, ON/OFF ratios of greater than 10^7, and ON current density greater than 250 uA/um, all at ~80 nm channel lengths. Our devices show stable retention up to 20000 secs and endurance up to 20000 cycles in addition to 4-bit pulse programmable memory features thereby opening a path towards scalable 3D hetero-integration of 2D semiconductor memory with Si CMOS logic.

physics.app-ph