11/30 專題演講公告

Hits:28

演講人：胡璧合 博士

服務單位：臺灣大學電機系

演講題目：Ferroelectric FET Non-volatile Memory

演講時間：109年11月30日(星期一)早上10點20分

演講地點：工綜館203國際演講廳

個人學歷：

國立交通大學/電子研究所/博士

國立交通大學/電子研究所/碩士

國立交通大學/材料科學與工程學系/學士

個人經歷：

國立台灣大學/電機工程學系/副教授 (現職)

國立中央大學/電機工程學系/副教授

國立中央大學/電機工程學系/助理教授

The Australian National University/Department of Electronic Materials Engineering/Visiting Scholar

University of California, Berkeley/Department of Electrical Engineering and Computer Sciences/Visiting Scholar

國立交通大學/智慧型記憶體及晶片系統實驗室/助理研究員

演講摘要：Artificial intelligence (AI) and Internet-of-Things (IoT) play a vital role in the future. For the von Neumann architecture, communication bottleneck between memory and processors becomes one of the most series problems due to low data throughput and high-power consumption. Non-volatile memory (NVM) based synapse and logic-in-memory circuit have been proposed to alleviate these problems. Ferroelectric Field-Effect-Transistor (FeFET) has been explored actively for emerging non-volatile memory and neuromorphic computing due to its high compatibility with CMOS platform. In this talk, I will introduce the operation principles and the challenges of FeFET memory. We have proposed a novel split-gate FeFET (SG-FeFET) for non-volatile memory and neuromorphic applications, which significantly improves the energy efficiency and reduces the power consumption. The reliability and endurance of SG-FeFET memory have also been improved owing to the lowered write voltage. SG-FeFET as a synaptic device has also been investigated including the non-linearity, asymmetry, and dynamic range of conductance updates.

11/23 專題演講公告

Hits:129

演講人： 莊家翔 博士

服務單位：中原大學電子工程系

演講題目：Investigations for magnetoresistance of ultralow-hole-density monolayer epitaxial graphene grown on SiC systems

演講時間：109年11月23日(星期一)早上10點20分

演講地點：工綜館203國際演講廳

個人學歷：

國立台灣大學/物理所/博士

個人經歷：

中原大學/電子工程學系/助理教授 (現職)

演講摘要：

In this talk, I focus on detailed measurements on ultralow-density p-type monolayer epitaxial graphene, which has yet to be extensively studied. The measured resistivity ρxx shows insulating behavior in the sense that ρxx decreases with increasing temperature T over a wide range of T (1.5 K ≤ T ≤ 300 K). The crossover from negative magnetoresistivity (MR) to positive magnetoresistivity at T = 40 K in the low-field regime is ascribed to a transition from low-T quantum transport to high-T classical transport. For T ≥ 120 K, the measured positive MR ratio [ρxx(B) − ρxx(B = 0)]/ρxx(B = 0) at B = 2 T decreases with increasing T, but the positive MR persists up to room temperature. Our experimental results suggest that the large MR ratio (~100% at B = 9 T) is an intrinsic property of ultralow-charge-density graphene, regardless of the carrier type. This effect may find applications in magnetic sensors and magnetoresistance devices.
Keywords: epitaxial graphene, resistance standard, magnetoresistance, quantum hall

11/16 專題演講公告

Hits:195

演講人：徐斌睿 博士

服務單位：清華大學物理系

演講題目：Proximity-Effect-Induced Superconductivity in Monatomic Ni-Pb Alloy and Ni Nanoislands

演講時間：109年11月16日(星期一)早上10點20分

演講地點：工綜館203國際演講廳

個人學歷：

國立中央大學 / 物理系 / 碩士

國立臺灣大學 / 物理所 / 博士

個人經歷：

國立清華大學 / 助理教授 (現職)

德國福茲堡大學/博士後研究

德國漢堡大學/博士後研究

演講摘要：

Proximity effect facilitates the penetration of Cooper pairs that permits superconductivity in normal metal with reduced dimensionality, offering a promising approach to develop novel quantum phenomena and emergent phases of matters in hybrid magnetic/superconducting nanostructures. Here, we have investigated proximity-induced superconductivity in monatomic Ni-Pb alloy and Ni nanoislands grown on Pb(111) by scanning tunneling microscopy/ spectroscopy (STM/STS) combined with theoretical calculations. Through elemental Pb superconducting substrate, tunneling conductance spectra have resolved an induced superconductivity with a gap size Δ about 0.85 meV in Ni-Pb alloy, which is about 0.11 meV smaller than Pb(111). On the contrary, Ni nanoislands with honeycomb lattice display a superconductivity gap with the same size of the Pb(111) substrate. From spatially monotonic decrease of Δ across the interface between Ni-Pb alloy and Pb(111), the decay length ξ_L about 5 nm has been extracted. According to the Usadel fittings and the BdG model, a weak ferromagnetism with an effective temperature about 6 ~ 15 K explains such rather short decay length as well as reduced superconductivity gap in the Ni-Pb surface alloy. As for honeycomb-structured Ni nanoislands, asymmetric edge scattering of surface electrons on Pb(111) has been revealed and further theoretical insights on the details of strong suppression of backscattering at the bearded type of edges are currently in progress.

11/02 專題演講公告

Hits:147

演講者：莊天明 博士

演講題目：Visualizing Emergent Superconductivity by Spectroscopic Imaging - Scanning Tunneling Microscopy

10/26(一)專題演講公告

Hits:260

演講者：吳欣潔 博士

演講題目：Phase diagram engineering - A New Avenue Towards High Performance Thermoelectric Materials

10/19(一)專題演講公告

Hits:168

演講者：楊展其 博士

演講題目：Advanced Growth and Manipulation of Complex Oxides

10/12(一)專題演講公告

Hits:206

演講者：李昀修先生

演講題目：走出巨塔，勇於開創，繞遠路的人生

10/05(一)專題演講公告

Hits:225

演講者：郭俞麟 博士

演講題目：Surface Treatment on Metals via Atmospheric Pressure Plasma

9/28(一)專題演講公告

Hits:218

演講者：莊子弘 研究員

演講題目：Photoemission electron microscopy at Taiwan Light Source and Taiwan Photon Source