Lower Bounds on Error Exponents via a New Quantum Decoder
- URL: http://arxiv.org/abs/2310.09014v2
- Date: Wed, 15 Nov 2023 10:50:03 GMT
- Title: Lower Bounds on Error Exponents via a New Quantum Decoder
- Authors: Salman Beigi and Marco Tomamichel
- Abstract summary: We show new lower bounds on the error exponent on the classical-quantum and the entanglement-assisted channel coding problem.
Our bounds are expressed in terms of measured (for the one-shot bounds) and sandwiched (for the bounds) channel R'enyi mutual information of order between 1/2 and 1.
- Score: 14.304623719903972
- License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
- Abstract: We introduce a new quantum decoder based on a variant of the pretty good
measurement, but defined via an alternative matrix quotient. We use this
decoder to show new lower bounds on the error exponent both in the one-shot and
asymptotic regimes for the classical-quantum and the entanglement-assisted
channel coding problem. Our bounds are expressed in terms of measured (for the
one-shot bounds) and sandwiched (for the asymptotic bounds) channel R\'enyi
mutual information of order between 1/2 and 1. Our results are not comparable
with some previously established bounds for general instances, yet they are
tight (for rates close to capacity) when the underlying channel is classical.
Related papers
- Resolvability of classical-quantum channels [54.825573549226924]
We study the resolvability of classical-quantum channels in two settings, for the channel output generated from the worst input, and form the fixed independent and identically distributed (i.i.d.) input.
For the fixed-input setting, while the direct part follows from the known quantum soft covering result, we exploit the recent alternative quantum Sanov theorem to solve the strong converse.
arXiv Detail & Related papers (2024-10-22T05:18:43Z) - Quantum Bayesian Optimization [64.58749619145908]
We introduce the quantum-Gaussian process-upper confidence bound (Q-GP-UCB) algorithm.
It is the first BO algorithm able to achieve a regret upper bound of O(polylog T), which is significantly smaller than its regret lower bound of Omega(sqrt(T)) in the classical setting.
Thanks to our novel analysis of the confidence ellipsoid, our Q-GP-UCB with the linear kernel achieves a smaller regret than the quantum linear UCB algorithm.
arXiv Detail & Related papers (2023-10-09T03:10:42Z) - Quantum soft-covering lemma with applications to rate-distortion coding, resolvability and identification via quantum channels [7.874708385247353]
We prove a one-shot quantum covering lemma in terms of smooth min-entropies.
We provide new upper bounds on the unrestricted and simultaneous identification capacities of quantum channels.
arXiv Detail & Related papers (2023-06-21T17:53:22Z) - Lossy Quantum Source Coding with a Global Error Criterion based on a
Posterior Reference Map [7.646713951724011]
We consider the lossy quantum source coding problem where the task is to compress a given quantum source below its von Neumann entropy.
Inspired by the duality connections between the rate-distortion and channel coding problems in the classical setting, we propose a new formulation for the problem.
arXiv Detail & Related papers (2023-02-01T17:44:40Z) - Quantum Worst-Case to Average-Case Reductions for All Linear Problems [66.65497337069792]
We study the problem of designing worst-case to average-case reductions for quantum algorithms.
We provide an explicit and efficient transformation of quantum algorithms that are only correct on a small fraction of their inputs into ones that are correct on all inputs.
arXiv Detail & Related papers (2022-12-06T22:01:49Z) - Quantum computation on a 19-qubit wide 2d nearest neighbour qubit array [59.24209911146749]
This paper explores the relationship between the width of a qubit lattice constrained in one dimension and physical thresholds.
We engineer an error bias at the lowest level of encoding using the surface code.
We then address this bias at a higher level of encoding using a lattice-surgery surface code bus.
arXiv Detail & Related papers (2022-12-03T06:16:07Z) - Computable lower bounds on the entanglement cost of quantum channels [8.37609145576126]
A class of lower bounds for the entanglement cost of any quantum state was recently introduced in [arXiv:2111.02438].
Here we extend their definitions to point-to-point quantum channels, establishing a lower bound for the quantum entanglement cost of any channel.
This leads to a bound that is computable as a semidefinite program and that can outperform previously known lower bounds.
arXiv Detail & Related papers (2022-01-23T13:05:36Z) - Reliable Simulation of Quantum Channels: the Error Exponent [5.8303977553652]
We study the error exponent of quantum channel simulation, which characterizes the optimal speed of exponential convergence.
We obtain an achievability bound for quantum channel simulation in the finite-blocklength setting.
arXiv Detail & Related papers (2021-12-08T18:55:54Z) - Tight Exponential Analysis for Smoothing the Max-Relative Entropy and
for Quantum Privacy Amplification [56.61325554836984]
The max-relative entropy together with its smoothed version is a basic tool in quantum information theory.
We derive the exact exponent for the decay of the small modification of the quantum state in smoothing the max-relative entropy based on purified distance.
arXiv Detail & Related papers (2021-11-01T16:35:41Z) - Dense Coding with Locality Restriction for Decoder: Quantum Encoders vs.
Super-Quantum Encoders [67.12391801199688]
We investigate dense coding by imposing various locality restrictions to our decoder.
In this task, the sender Alice and the receiver Bob share an entangled state.
arXiv Detail & Related papers (2021-09-26T07:29:54Z) - Novel one-shot inner bounds for unassisted fully quantum channels via rate splitting [4.642647756403863]
We prove the first non-trivial one-shot inner bounds for sending quantum information over an entanglement over an unassisted two-sender quantum multiple access channel (QMAC) and an unassisted two-sender two-receiver quantum interference channel (QIC)
Previous works only studied the unassisted QMAC in the limit of many independent and identical uses of the channel also known as the iid limit, and did not study the unassisted QIC at all.
arXiv Detail & Related papers (2021-02-02T21:36:09Z)
This list is automatically generated from the titles and abstracts of the papers in this site.
This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.