882 research outputs found
Transistor performance of top rough surface of pentacene measured by laminated double insulated-gate supported on a poly(dimethylsiloxanes) base structure
We report the fabrication and electrical characterization of pentacene field-effect transistors with a laminated double insulated-gate using poly(dimethylsiloxanes) (PDMS) as their supporting structure. The ability of PDMS to conform to surfaces enables us to directly evaluate the device performance of the top rough surface of the pentacene active layer (the pentacene-air interface). The mobility measured for the top surface was only about 20% slightly lower than that of the bottom surface. Device stability under ambient conditions is evaluated. This device structure is useful for the characterization of electrical transport in both the top and bottom surface of a thin film simultaneously.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87784/2/033502_1.pd
Quantum information processing architecture with endohedral fullerenes in a carbon nanotube
A potential quantum information processor is proposed using a fullerene
peapod, i.e., an array of the endohedral fullerenes 15N@C60 or 31P@C60
contained in a single walled carbon nanotube (SWCNT). The qubits are encoded in
the nuclear spins of the doped atoms, while the electronic spins are used for
initialization and readout, as well as for two-qubit operations.Comment: 8 pages, 8 figure
No spin-localization phase transition in the spin-boson model without local field
We explore the spin-boson model in a special case, i.e., with zero local
field. In contrast to previous studies, we find no possibility for quantum
phase transition (QPT) happening between the localized and delocalized phases,
and the behavior of the model can be fully characterized by the even or odd
parity as well as the parity breaking, instead of the QPT, owned by the ground
state of the system. Our analytical treatment about the eigensolution of the
ground state of the model presents for the first time a rigorous proof of
no-degeneracy for the ground state of the model, which is independent of the
bath type, the degrees of freedom of the bath and the calculation precision. We
argue that the QPT mentioned previously appears due to unreasonable treatment
of the ground state of the model or of the infrared divergence existing in the
spectral functions for Ohmic and sub-Ohmic dissipations.Comment: 5 pages, 1 figure. Comments are welcom
Negative Pre-aware for Noisy Cross-modal Matching
Cross-modal noise-robust learning is a challenging task since noisy
correspondence is hard to recognize and rectify. Due to the cumulative and
unavoidable negative impact of unresolved noise, existing methods cannot
maintain a stable performance when the noise increases. In this paper, we
present a novel Negative Pre-aware Cross-modal (NPC) matching solution for
large visual-language model fine-tuning on noisy downstream tasks. It is
featured in two aspects: (1) For noise recognition and resistance, previous
methods usually directly filter out a noise subset, we propose to estimate the
negative impact of each sample. It does not need additional correction
mechanisms that may predict unreliable correction results, leading to
self-reinforcing error. We assign a confidence weight to each sample according
to its negative impact in the training process. This adaptively adjusts the
contribution of each sample to avoid noisy accumulation. (2) For maintaining
stable performance with increasing noise, we utilize the memorization effect of
DNNs by maintaining a memory bank. Specifically, we apply GMM to select
high-confident clean samples as the memory entry, where the memory entry is
used to estimate the negative impact of each sample. Since clean samples are
easier distinguished by GMM with increasing noise, the memory bank can still
maintain high quality at a high noise ratio. Compared to the correction
mechanism focusing on noise samples, memory bank-based estimation is more
robust, which makes the model performance stable on noisy datasets. Extensive
experiments demonstrate that our method significantly improves matching
accuracy and performance stability at increasing noise ratio. Our approach also
surpasses the state-of-the-art methods by a large margin. The code is available
at: https://github.com/ZhangXu0963/NPC.Comment: 9 pages, 5 figures, conferenc
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