1,652 research outputs found
Half-Heusler Compounds as a New Class of Three-Dimensional Topological Insulators
Using first-principles calculations within density functional theory, we
explore the feasibility of converting ternary half-Heusler compounds into a new
class of three-dimensional topological insulators (3DTI). We demonstrate that
the electronic structure of unstrained LaPtBi as a prototype system exhibits
distinct band-inversion feature. The 3DTI phase is realized by applying a
uniaxial strain along the [001] direction, which opens a bandgap while
preserving the inverted band order. A definitive proof of the strained LaPtBi
as a 3DTI is provided by directly calculating the topological Z2 invariants in
systems without inversion symmetry. We discuss the implications of the present
study to other half-Heusler compounds as 3DTI, which, together with the
magnetic and superconducting properties of these materials, may provide a rich
platform for novel quantum phenomena.Comment: 4 pages, 5 figures; Phys. Rev. Lett. (in press
REST: Retrieval-Based Speculative Decoding
We introduce Retrieval-Based Speculative Decoding (REST), a novel algorithm
designed to speed up language model generation. The key insight driving the
development of REST is the observation that the process of text generation
often includes certain common phases and patterns. Unlike previous methods that
rely on a draft language model for speculative decoding, REST harnesses the
power of retrieval to generate draft tokens. This method draws from the
reservoir of existing knowledge, retrieving and employing relevant tokens based
on the current context. Its plug-and-play nature allows for seamless
integration and acceleration of any language models, all without necessitating
additional training. When benchmarked on 7B and 13B language models in a
single-batch setting, REST achieves a significant speedup of 1.62X to 2.36X on
code or text generation. The code of REST is available at
https://github.com/FasterDecoding/REST
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