arXiv subjects

Yaofeng Chen

Publications and source records attributed to Yaofeng Chen.

3 recordsLinked to original sources

arXiv2026

Generating large-scale Greenberger-Horne-Zeilinger-like states in lattice spin systems

Greenberger-Horne-Zeilinger (GHZ) state is a typical maximally entangled state which is pursued in both fundamental research and emerging quantum technologies. Preparing large-scale GHZ states in lattice spin systems is particularly appealing for quantum advantages, but conventional schemes face great challenges in scalability. Here we propose a universal and scalable scheme to generate large-scale GHZ-like states, which share similar entanglement and metrological properties with standard GHZ states, in lattice spin systems through global Floquet engineering. Our scheme requires only global operations and shows great advantage for large particle number. It is applicable to systems with arbitrary interaction ranges, offering a practical pathway for large-scale implementation of many-body entangled states in various systems.

quant-ph↗

arXiv2016

Role of Pressure in the Growth of Hexagonal Boron Nitride Thin Films from Ammonia-Borane

We analyze the optical, chemical, and electrical properties of chemical vapor deposition (CVD) grown hexagonal boron nitride (h-BN) using the precursor ammonia-borane ($H_3N-BH_3$) as a function of $Ar/H_2$ background pressure ($P_{TOT}$). Films grown at $P_{TOT}$ less than 2.0 Torr are uniform in thickness, highly crystalline, and consist solely of h-BN. At larger $P_{TOT}$, with constant precursor flow, the growth rate increases, but the resulting h-BN is more amorphous, disordered, and $sp^3$ bonded. We attribute these changes in h-BN grown at high pressure to incomplete thermolysis of the $H_3N-BH_3$ precursor from a passivated Cu catalyst. A similar increase in h-BN growth rate and amorphization is observed even at low $P_{TOT}$ if the $H_3N-BH_3$ partial pressure is initially greater than the background pressure $P_{TOT}$ at the beginning of growth. h-BN growth using the $H_3N-BH_3$ precursor reproducibly can give large-area, crystalline h-BN thin films, provided that the total pressure is under 2.0 Torr and the precursor flux is well-controlled.

cond-mat.mtrl-sci↗

arXiv2015

Annealing Free, Clean Graphene Transfer using Alternative Polymer Scaffolds

We examine the transfer of graphene grown by chemical vapor deposition (CVD) with polymer scaffolds of poly(methyl methacrylate) (PMMA), poly(lactic acid) (PLA), poly(phthalaldehyde) (PPA), and poly(bisphenol A carbonate) (PC). We find that optimally reactive PC scaffolds provide the cleanest graphene transfers without any annealing, after extensive comparison with optical microscopy, X-ray photoelectron spectroscopy, atomic force microscopy, and scanning tunneling microscopy. Comparatively, films transferred with PLA, PPA, and PMMA have a two-fold higher roughness and a five-fold higher chemical doping. Using PC scaffolds, we demonstrate the clean transfer of CVD multilayer graphene, fluorinated graphene, and hexagonal boron nitride. Our annealing free, PC transfers enable the use of atomically-clean nanomaterials in biomolecule encapsulation and flexible electronic applications.

cond-mat.mtrl-sci↗