arXiv subjects

Jimmy Qin

Publications and source records attributed to Jimmy Qin.

4 recordsLinked to original sources

arXiv2026

Contacts to Low-Dimensional Semiconductors: Physical Theory and Analytical Model

Metal contacts to low-dimensional semiconductors are critical for nanoelectronics, yet a general physical description has remained elusive. We present an analytical model for metal-induced gap states (MIGS), revealing a universal scaling law governed by semiconductor dimensionality. Linking MIGS to transport observables, we provide a unified formulation of Schottky barrier height, transfer length, and contact resistance. Our model explains recent experiments on carbon nanotubes and 2D materials, clarifying the fundamental criteria for achieving scalable, low-resistance contacts.

cond-mat.mes-hall↗

arXiv2025

Gate Dielectric Engineering with an Ultrathin Silicon-oxide Interfacial Dipole Layer for Low-Leakage Oxide-Semiconductor Memories

We demonstrate a gate dielectric engineering approach leveraging an ultrathin, atomic layer deposited (ALD) silicon oxide interfacial layer (SiL) between the amorphous oxide semiconductor (AOS) channel and the high-k gate dielectric. SiL positively shifts the threshold voltage (V$_T$) of AOS transistors, providing at least four distinct $V_T$ levels with a maximum increase of 500 mV. It achieves stable $V_T$ control without significantly degrading critical device parameters such as mobility, on-state current, all while keeping the process temperature below 225 $^{\circ}$C and requiring no additional heat treatment to activate the dipole. Positive-bias temperature instability tests at 85 $^{\circ}$C indicate a significant reduction in negative $V_{T}$ shifts for SiL-integrated devices, highlighting enhanced reliability. Incorporating this SiL gate stack into two-transistor gain-cell (GC) memory maintains a more stable storage node voltage ($V_{SN}$) (reduces $V_{SN}$ drop by 67\%), by limiting unwanted charge losses. SiL-engineered GCs also reach retention times up to 10,000 s at room temperature and reduce standby leakage current by three orders of magnitude relative to baseline device, substantially lowering refresh energy consumption.

cond-mat.mtrl-sci↗

arXiv2023

New News is Bad News

An increase in the novelty of news predicts negative stock market returns and negative macroeconomic outcomes over the next year. We quantify news novelty - changes in the distribution of news text - through an entropy measure, calculated using a recurrent neural network applied to a large news corpus. Entropy is a better out-of-sample predictor of market returns than a collection of standard measures. Cross-sectional entropy exposure carries a negative risk premium, suggesting that assets that positively covary with entropy hedge the aggregate risk associated with shifting news language. Entropy risk cannot be explained by existing long-short factors.

q-fin.GN↗

arXiv2019

Recurrent Attentive Neural Process for Sequential Data

Neural processes (NPs) learn stochastic processes and predict the distribution of target output adaptively conditioned on a context set of observed input-output pairs. Furthermore, Attentive Neural Process (ANP) improved the prediction accuracy of NPs by incorporating attention mechanism among contexts and targets. In a number of real-world applications such as robotics, finance, speech, and biology, it is critical to learn the temporal order and recurrent structure from sequential data. However, the capability of NPs capturing these properties is limited due to its permutation invariance instinct. In this paper, we proposed the Recurrent Attentive Neural Process (RANP), or alternatively, Attentive Neural Process-RecurrentNeural Network(ANP-RNN), in which the ANP is incorporated into a recurrent neural network. The proposed model encapsulates both the inductive biases of recurrent neural networks and also the strength of NPs for modelling uncertainty. We demonstrate that RANP can effectively model sequential data and outperforms NPs and LSTMs remarkably in a 1D regression toy example as well as autonomous-driving applications.

cs.LG↗