Joseph M. Renes

Last Name

Renes

First Name

Joseph M.

ORCID

0000-0003-2302-8025

Organisational unit

03781 - Renner, Renato / Renner, Renato

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Publications 1 - 10 of 109

Toward Low-latency Iterative Decoding of QLDPC Codes Under Circuit-Level Noise
Gong, Anqi; Cammerer, Sebastian; Renes, Joseph M. (2024)
arXiv
We introduce a sliding window decoder based on belief propagation (BP) with guided decimation for the purposes of decoding quantum low-density parity-check codes in the presence of circuit-level noise. Windowed decoding keeps the decoding complexity reasonable when, as is typically the case, repeated rounds of syndrome extraction are required to decode. Within each window, we employ several rounds of BP with decimation of the variable node that we expect to be the most likely to flip in each round, Furthermore, we employ ensemble decoding to keep both decimation options (guesses) open in a small number of chosen rounds. We term the resulting decoder BP with guided decimation guessing (GDG). Applied to bivariate bicycle codes, GDG achieves a similar logical error rate as BP with an additional OSD post-processing stage (BP+OSD) and combination-sweep of order 10. For a window size of three syndrome cycles, a multi-threaded CPU implementation of GDG achieves a worst-case decoding latency of 3ms per window for the [[144,12,12]] code.
Lower Bounds for Quantum Parameter Estimation
Walter, Michael; Renes, Joseph M. (2014)
IEEE Transactions on Information Theory
Symmetric extension in two-way quantum key distribution
Myhr, Geir O.; Renes, Joseph M.; Doherty, Andrew C.; et al. (2009)
Physical Review A
We introduce symmetric extensions of bipartite quantum states as a tool for analyzing protocols that distill secret key from quantum correlations. Whether the correlations are coming from a prepare-and-measure quantum key distribution scheme or from an entanglement-based scheme, the protocol has to produce effective states without a symmetric extension in order to succeed. By formulating the symmetric extension problem as a semidefinite program, we solve the problem for Bell-diagonal states. Applying this result to the six-state and Bennett-Brassard 1984 schemes, we show that for the entangled states that cannot be distilled by current key distillation procedures, the failure can be understood in terms of a failure to break a symmetric extension. ©2009 American Physical Society
Quantum dichotomies and coherent thermodynamics beyond first-order asymptotics
Lipka-Bartosik, Patryk; Chubb, Christopher; Renes, Joseph M.; et al. (2023)
arXiv
We address the problem of exact and approximate transformation of quantum dichotomies in the asymptotic regime, i.e., the existence of a quantum channel E mapping ρ⊗n1 into ρ⊗Rnn2 with an error ϵn (measured by trace distance) and σ⊗n1 into σ⊗Rnn2 exactly, for a large number n. We derive second-order asymptotic expressions for the optimal transformation rate Rn in the small, moderate, and large deviation error regimes, as well as the zero-error regime, for an arbitrary pair (ρ1,σ1) of initial states and a commuting pair (ρ2,σ2) of final states. We also prove that for σ1 and σ2 given by thermal Gibbs states, the derived optimal transformation rates in the first three regimes can be attained by thermal operations. This allows us, for the first time, to study the second-order asymptotics of thermodynamic state interconversion with fully general initial states that may have coherence between different energy eigenspaces. Thus, we discuss the optimal performance of thermodynamic protocols with coherent inputs and describe three novel resonance phenomena allowing one to significantly reduce transformation errors induced by finite-size effects. What is more, our result on quantum dichotomies can also be used to obtain, up to second-order asymptotic terms, optimal conversion rates between pure bipartite entangled states under local operations and classical communication.
Belief propagation decoding of quantum channels by passing quantum messages
Renes, Joseph M. (2016)
arXiv
The Resource Theory of Quantum States Out of Thermal Equilibrium
Brandao, Fernando G.S.L.; Horodecki, Michał; Oppenheim, Jonathan; et al. (2011)
arXiv
The ideas of thermodynamics have proved fruitful in the setting of quantum information theory, in particular the notion that when the allowed transformations of a system are restricted, certain states of the system become useful resources with which one can prepare previously inaccessible states. The theory of entanglement is perhaps the best-known and most well-understood resource theory in this sense. Here we return to the basic questions of thermodynamics using the formalism of resource theories developed in quantum information theory and show that the free energy of thermodynamics emerges naturally from the resource theory of energy-preserving transformations. Specifically, the free energy quantifies the amount of useful work which can be extracted from asymptotically-many copies of a quantum system when using only reversible energy-preserving transformations and a thermal bath at fixed temperature. The free energy also quantifies the rate at which resource states can be reversibly interconverted asymptotically, provided that a sublinear amount of coherent superposition over energy levels is available, a situation analogous to the sublinear amount of classical communication required for entanglement dilution.
Identifying the Information Gain of a Quantum Measurement
Berta, Mario; Renes, Joseph M.; Wilde, Mark M. (2013)
arXiv
Improved Logical Error Rate via List Decoding of Quantum Polar Codes
Gong, Anqi; Renes, Joseph M. (2023)
arXiv
The successive cancellation list decoder (SCL) is an efficient decoder for classical polar codes with low decoding error, approximating the maximum likelihood decoder (MLD) for small list sizes. Here we adapt the SCL to the task of decoding quantum polar codes and show that it inherits the high performance and low complexity of the classical case, and can approximate the quantum MLD for certain channels. We apply SCL decoding to a novel version of quantum polar codes based on the polarization weight (PW) method, which entirely avoids the need for small amounts of entanglement assistance apparent in previous quantum polar code constructions. When used to find the precise error pattern, the quantum SCL decoder (SCL-E) shows competitive performance with surface codes of similar size and low-density parity check codes of similar size and rate. The SCL decoder may instead be used to approximate the probability of each equivalence class of errors, and then choose the most likely class. We benchmark this class-oriented decoder (SCL-C) against the SCL-E decoder and find a noticeable improvement in the logical error rate. This improvement stems from the fact that the contributions from just the low-weight errors give a reasonable approximation to the error class probabilities. Both SCL-E and SCL-C maintain the complexity O(LN logN) of SCL for code size N and list size L. We also show that the list decoder can be used to gain insight into the weight distribution of the codes and how this impacts the effect of degenerate errors.
On privacy amplification, lossy compression, and their duality to channel coding
Renes, Joseph M. (2018)
IEEE Transactions on Information Theory
Equiangular tight frames from Paley tournaments
Renes, Joseph M. (2007)
Linear Algebra and its Applications
We prove the existence of equiangular tight frames having n = 2 d - 1 elements drawn from either Cd or Cd - 1 whenever n is either 2k - 1 for k ∈ N, or a power of a prime such that n ≡ 3 mod 4. We also find a simple explicit expression for the prime power case by establishing a connection to a 2 d-element equiangular tight frame based on quadratic residues. © 2007 Elsevier Inc. All rights reserved.

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Joseph M. Renes

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