30,787 research outputs found
Towards Efficient and Trustworthy AI Through Hardware-Algorithm-Communication Co-Design
Artificial intelligence (AI) algorithms based on neural networks have been
designed for decades with the goal of maximising some measure of accuracy. This
has led to two undesired effects. First, model complexity has risen
exponentially when measured in terms of computation and memory requirements.
Second, state-of-the-art AI models are largely incapable of providing
trustworthy measures of their uncertainty, possibly `hallucinating' their
answers and discouraging their adoption for decision-making in sensitive
applications.
With the goal of realising efficient and trustworthy AI, in this paper we
highlight research directions at the intersection of hardware and software
design that integrate physical insights into computational substrates,
neuroscientific principles concerning efficient information processing,
information-theoretic results on optimal uncertainty quantification, and
communication-theoretic guidelines for distributed processing. Overall, the
paper advocates for novel design methodologies that target not only accuracy
but also uncertainty quantification, while leveraging emerging computing
hardware architectures that move beyond the traditional von Neumann digital
computing paradigm to embrace in-memory, neuromorphic, and quantum computing
technologies. An important overarching principle of the proposed approach is to
view the stochasticity inherent in the computational substrate and in the
communication channels between processors as a resource to be leveraged for the
purpose of representing and processing classical and quantum uncertainty
Multicore Quantum Computing
Any architecture for practical quantum computing must be scalable. An
attractive approach is to create multiple cores, computing regions of fixed
size that are well-spaced but interlinked with communication channels. This
exploded architecture can relax the demands associated with a single monolithic
device: the complexity of control, cooling and power infrastructure as well as
the difficulties of cross-talk suppression and near-perfect component yield.
Here we explore interlinked multicore architectures through analytic and
numerical modelling. While elements of our analysis are relevant to diverse
platforms, our focus is on semiconductor electron spin systems in which
numerous cores may exist on a single chip. We model shuttling and
microwave-based interlinks and estimate the achievable fidelities, finding
values that are encouraging but markedly inferior to intra-core operations. We
therefore introduce optimsed entanglement purification to enable high-fidelity
communication, finding that is a very realistic goal. We then assess
the prospects for quantum advantage using such devices in the NISQ-era and
beyond: we simulate recently proposed exponentially-powerful error mitigation
schemes in the multicore environment and conclude that these techniques
impressively suppress imperfections in both the inter- and intra-core
operations.Comment: 26 pages, 16 Figure
Quantum Information Complexity and Amortized Communication
We define a new notion of information cost for quantum protocols, and a
corresponding notion of quantum information complexity for bipartite quantum
channels, and then investigate the properties of such quantities. These are the
fully quantum generalizations of the analogous quantities for bipartite
classical functions that have found many applications recently, in particular
for proving communication complexity lower bounds. Our definition is strongly
tied to the quantum state redistribution task.
Previous attempts have been made to define such a quantity for quantum
protocols, with particular applications in mind; our notion differs from these
in many respects. First, it directly provides a lower bound on the quantum
communication cost, independent of the number of rounds of the underlying
protocol. Secondly, we provide an operational interpretation for quantum
information complexity: we show that it is exactly equal to the amortized
quantum communication complexity of a bipartite channel on a given state. This
generalizes a result of Braverman and Rao to quantum protocols, and even
strengthens the classical result in a bounded round scenario. Also, this
provides an analogue of the Schumacher source compression theorem for
interactive quantum protocols, and answers a question raised by Braverman.
We also discuss some potential applications to quantum communication
complexity lower bounds by specializing our definition for classical functions
and inputs. Building on work of Jain, Radhakrishnan and Sen, we provide new
evidence suggesting that the bounded round quantum communication complexity of
the disjointness function is \Omega (n/M + M), for M-message protocols. This
would match the best known upper bound.Comment: v1, 38 pages, 1 figur
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