Browsing by Author "Huang, Szu-Jung"

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Active and passive compensation of APPLE II-introduced multipole errors through beam-based measurement
(2016-08-01)
Chung, Ting-Yi
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Huang, Szu-Jung
;
Fu, Huang-Wen
;
Chang, Ho-Ping
;
Chang, Cheng-Hsiang
The effect of an APPLE II-type elliptically polarized undulator (EPU) on the beam dynamics were investigated using active and passive methods. To reduce the tune shift and improve the injection efficiency, dynamic multipole errors were compensated using L-shaped iron shims, which resulted in stable top-up operation for a minimum gap. The skew quadrupole error was compensated using a multipole corrector, which was located downstream of the EPU for minimizing betatron coupling, and it ensured the enhancement of the synchrotron radiation brightness. The investigation methods, a numerical simulation algorithm, a multipole error correction method, and the beam-based measurement results are discussed. (C) 2016 Elsevier B.V. All rights reserved.
Pulse-Driven Nonvolatile Perovskite Memory with Photovoltaic Read-Out Characteristics
(2019-09-18)
Chang, Shu-Jui
;
Chen, Syuan-Ye
;
Chen, Po-Wen
;
Huang, Szu-Jung
;
Tseng, Yuan-Chieh
This paper presents a unique GdFe08Ni0.2O3 perovskite thin film for use in pulse-controlled nonvolatile memory devices (combined with a SrTiO3 (STO) substrate) without the need for an electrical-stressing read-out process. The use of pulse voltage imposes permanent downward/upward polarization states on GFNO, which enables greater energy density and higher energy efficiency than the unpoled state for memory. The two polarization states produce carrier migrations in opposing directions across the GFNO/STO interface, which alter the depletion region of the device, as reflected in photovoltaic short-circuit current density (J(sc)) values. Modulating the duration (varying the number of sequential pulses but fixing the pulse width and delay time) and direction of continuous pulse voltage is an effective method for controlling J(sc), thereby allowing the fabrication of nondestructive, light-tunable, nonvolatile memory devices. In experiments, J(sc) in the downward polarized state was approximately 6 times greater than that in the upward polarized state. It is promising that more memory states can be enabled by the proposed heterostructure by selecting appropriate pulse trains. Real-time interfacial changes (relative to the nonvolatile characteristics of the device) were obtained by applying synchrotron X-ray techniques simultaneously with pulse characterization. This made it possible to separately probe the electronic and chemical states of the GFNO (a p-type-like semiconductor) and STO (an n-type-like semiconductor) while varying the pulse direction, thereby making it possible to identify the mechanisms underlying the observed phenomena.