2,328 research outputs found
Teleportation-Based Quantum Computation, Extended Temperley-Lieb Diagrammatical Approach and Yang--Baxter Equation
This paper focuses on the study of topological features in
teleportation-based quantum computation as well as aims at presenting a
detailed review on teleportaiton-based quantum computation (Gottesman and
Chuang, Nature 402, 390, 1999). In the extended Temperley-Lieb diagrammatical
approach, we clearly show that such topological features bring about the
fault-tolerant construction of both universal quantum gates and four-partite
entangled states more intuitive and simpler. Furthermore, we describe the
Yang--Baxter gate by its extended Temperley-Lieb configuration, and then study
teleportation-based quantum circuit models using the Yang--Baxter gate.
Moreover, we discuss the relationship between the extended Temperley-Lieb
diagrammatical approach and the Yang-Baxter gate approach. With these research
results, we propose a worthwhile subject, the extended Temperley-Lieb
diagrammatical approach, for physicists in quantum information and quantum
computation.Comment: Latex, 47 pages, many figure
Effects of Graphene/BN Encapsulation, Surface Functionalization and Molecular Adsorption on the Electronic Properties of Layered InSe: A First-Principles Study
By using first-principles calculations, we investigated the effects of
graphene/boron nitride (BN) encapsulation, surface functionalization by
metallic elements (K, Al, Mg and typical transition metals) and molecules
(tetracyanoquinodimethane (TCNQ) and tetracyanoethylene (TCNE)) on the
electronic properties of layered indium selenide (InSe). It was found that an
opposite trend of charge transfer is possible for graphene (donor) and BN
(acceptor), which is dramatically different from phosphorene where both
graphene and BN play the same role (donor). For InSe/BN heterostructure, a
change of the interlayer distance due to an out-of-plane compression can
effectively modulate the band gap. Strong acceptor abilities to InSe were found
for the TCNE and TCNQ molecules. For K, Al and Mg-doped monolayer InSe, the
charge transfer from K and Al atoms to the InSe surface was observed, causing
an n-type conduction of InSe, while p-type conduction of InSe observed in case
of the Mg-doping. The atomically thin structure of InSe enables the possible
observation and utilization of the dopant-induced vertical electric field
across the interface. A proper adoption of the n- or p-type dopants allows for
the modulation of the work function, the Fermi level pinning, the band bending,
and the photo-adsorbing efficiency near the InSe surface/interface.
Investigation on the adsorption of transition metal atoms on InSe showed that
Ti-, V-, Cr-, Mn-, Co-adsorbed InSe are spin-polarized, while Ni-, Cu-, Pd-,
Ag- and Au-adsorbed InSe are non-spin-polarized. Our results shed lights on the
possible ways to protect InSe structure and modulate its electronic properties
for nanoelectronics and electrochemical device applications
Exploring the Charge Localization and Band Gap Opening of Borophene: A First-Principles Study
Recently synthesized two-dimensional (2D) boron, borophene, exhibits a novel
metallic behavior rooted in the s-p orbital hybridization, distinctively
different from other 2D materials such as sulfides/selenides and semi-metallic
graphene. This unique feature of borophene implies new routes for charge
delocalization and band gap opening. Herein, using first-principles
calculations, we explore the routes to localize the carriers and open the band
gap of borophene via chemical functionalization, ribbon construction, and
defect engineering. The metallicity of borophene is found to be remarkably
robust against H- and F-functionalization and the presence of vacancies.
Interestingly, a strong odd-even oscillation of the electronic structure with
width is revealed for H-functionalized borophene nanoribbons, while an
ultra-high work function (~ 7.83 eV) is found for the F-functionalized
borophene due to its strong charge transfer to the atomic adsorbates
Large Electronic Anisotropy and Enhanced Chemical Activity of Highly Rippled Phosphorene
We investigate the electronic structure and chemical activity of rippled
phosphorene induced by large compressive strains via first-principles
calculation. It is found that phosphorene is extraordinarily bendable, enabling
the accommodation of ripples with large curvatures. Such highly rippled
phosphorene shows a strong anisotropy in electronic properties. For ripples
along the armchair direction, the band gap changes from 0.84 to 0.51 eV for the
compressive strain up to -20% and further compression shows no significant
effect, for ripples along the zigzag direction, semiconductor to metal
transition occurs. Within the rippled phosphorene, the local electronic
properties, such as the modulated band gap and the alignments of frontier
orbitals, are found to be highly spatially dependent, which may be used for
modulating the injection and confinement of carriers for optical and
photovoltaic applications. The examination of the interaction of a physisorbed
NO molecule with the rippled phosphorene under different compressive strains
shows that the chemical activities of the phosphorene are significantly
enhanced at the top and bottom peaks of the ripples, indicated by the enhanced
adsorption and charge transfer between them. All these features can be ascribed
to the effect of curvatures, which modifies the orbital coupling between atoms
at the ripple peaks
SurgicalSAM: Efficient Class Promptable Surgical Instrument Segmentation
The Segment Anything Model (SAM) is a powerful foundation model that has
revolutionised image segmentation. To apply SAM to surgical instrument
segmentation, a common approach is to locate precise points or boxes of
instruments and then use them as prompts for SAM in a zero-shot manner.
However, we observe two problems with this naive pipeline: (1) the domain gap
between natural objects and surgical instruments leads to poor generalisation
of SAM; and (2) SAM relies on precise point or box locations for accurate
segmentation, requiring either extensive manual guidance or a well-performing
specialist detector for prompt preparation, which leads to a complex
multi-stage pipeline. To address these problems, we introduce SurgicalSAM, a
novel end-to-end efficient-tuning approach for SAM to effectively integrate
surgical-specific information with SAM's pre-trained knowledge for improved
generalisation. Specifically, we propose a lightweight prototype-based class
prompt encoder for tuning, which directly generates prompt embeddings from
class prototypes and eliminates the use of explicit prompts for improved
robustness and a simpler pipeline. In addition, to address the low inter-class
variance among surgical instrument categories, we propose contrastive prototype
learning, further enhancing the discrimination of the class prototypes for more
accurate class prompting. The results of extensive experiments on both
EndoVis2018 and EndoVis2017 datasets demonstrate that SurgicalSAM achieves
state-of-the-art performance while only requiring a small number of tunable
parameters. The source code will be released at
https://github.com/wenxi-yue/SurgicalSAM.Comment: Technical Report. The source code will be released at
https://github.com/wenxi-yue/SurgicalSA
Dynamical spontaneous scalarization in Einstein-Maxwell-scalar models in anti-de Sitter spacetime
The phenomenon of spontaneous scalarization of charged black holes has
attracted a lot of attention. In this work, we study the dynamical process of
the spontaneous scalarization of charged black hole in asymptotically anti-de
Sitter spacetimes in Einstein-Maxwell-scalar models. Including various
non-minimal couplings between the scalar field and Maxwell field, we observe
that an initial scalar-free configuration suffers tachyonic instability and
both the scalar field and the black hole irreducible mass grow exponentially at
early times and saturate exponentially at late times. For fractional couplings,
we find that though there is negative energy distribution near the black hole
horizon, the black hole horizon area never decreases. But when the parameters
are large, the evolution endpoints of linearly unstable bald black holes will
be spacetimes with naked singularity and the cosmic censorship is violated. The
effects of the black hole charge, cosmological constant and coupling strength
on the dynamical scalarization process are studied in detail. We find that
large enough cosmological constant can prevent the spontaneous scalarization.Comment: 20pages,8figure
Deletion or insertion in the first immunoglobulin-plexin-transcription (IPT) domain differentially regulates expression and tumorigenic activities of RON receptor Tyrosine Kinase
<p>Abstract</p> <p>Background</p> <p>Activation of the RON receptor tyrosine kinase, a member of the c-MET family, regulates tumorigenic phenotypes. The RON extracellular domains are critical in regulating these activities. The objective of this study was to determine the role of the first IPT domain in regulating RON-mediated tumorigenic activities and the underlying mechanisms.</p> <p>Results</p> <p>Two RON variants, RON160 and RON<sup>E5/6in </sup>with deletion and insertion in the first IPT domain, respectively, were molecularly cloned. RON160 was a splicing variant generated by deletion of 109 amino acids encoded by exons 5 and 6. In contrast, RON<sup>E5/6in </sup>was derived from a transcript with an insertion of 20 amino acids between exons 5 and 6. Both RON160 and RON<sup>E5/6in </sup>were proteolytically matured into two-chain receptor and expressed on the cell surface. RON160 was constitutively active with tyrosine phosphorylation. However, activation of RON<sup>E5/6in </sup>required ligand stimulation. Deletion resulted in the resistance of RON160 to proteolytic digestion by cell associated trypsin-like enzymes. RON160 also resisted anti-RON antibody-induced receptor internalization. These features contributed to sustained intracellular signaling cascades. On the other hand, RON<sup>E5/6in </sup>was highly susceptible to protease digestion, which led to formation of a truncated variant known as RONp110. RON<sup>E5/6in </sup>also underwent rapid internalization upon anti-RON antibody treatment, which led to signaling attenuation. Although ligand-induced activation of RON<sup>E5/6in </sup>partially caused epithelial to mesenchymal transition (EMT), it was RON160 that showed cell-transforming activities in cell focus formation and anchorage-independent growth. RON160-mediated EMT is also associated with increased motile/invasive activity.</p> <p>Conclusions</p> <p>Alterations in the first IPT domain in extracellular region differentially regulate RON mediated tumorigenic activities. Deletion of the first IPT results in formation of oncogenic variant RON160. Enhanced degradation and internalization with attenuated signaling cascades could be the mechanisms underlying non-tumorigenic features of RON<sup>E5/6in</sup>.</p
- …