234 citations · 1.6k across the 33 of their papers we have counts for
33 papers
Quantum Gaussian processes for prediction of channel observations
Jonas Jäger, Yaroslav Khmelnitskiy, Paolo Braccia +4
Given a set of input states, we consider the task of predicting the expectation value of a Pauli observable at the output of an unknown quantum evolution, using only a limited numb…
Evaluating the Limits of QAOA Parameter Transfer at High-Rounds on Sparse Ising Models With Geometrically Local Cubic Terms
Elijah Pelofske, Marek Rams, Andreas Bärtschi +4
The emergent practical applicability of the Quantum Approximate Optimization Algorithm (QAOA) for approximate combinatorial optimization is a subject of considerable interest. One…
Efficient Online Quantum Circuit Learning with No Upfront Training
Tom O'Leary, Piotr Czarnik, Elijah Pelofske +3
We propose a surrogate-based method for optimizing parameterized quantum circuits which is designed to operate with few calls to a quantum computer. We employ a computationally ine…
Robust design under uncertainty in quantum error mitigation
Maksym Prodius, Piotr Czarnik, Michael McKerns +2
Error mitigation techniques are crucial to achieving near-term quantum advantage. Classical post-processing of quantum computation outcomes is a popular approach for error mitigati…
A framework of partial error correction for intermediate-scale quantum computers
Nikolaos Koukoulekidis, Samson Wang, Tom O'Leary +3
As quantum computing hardware steadily increases in qubit count and quality, one important question is how to allocate these resources to mitigate the effects of hardware noise. In…
Large-scale simulations of Floquet physics on near-term quantum computers
Timo Eckstein, Refik Mansuroglu, Piotr Czarnik +5
Periodically driven quantum systems exhibit a diverse set of phenomena but are more challenging to simulate than their equilibrium counterparts. Here, we introduce the Quantum High…
Finite temperature tensor network study of the Hubbard model on an infinite square lattice
Aritra Sinha, Marek M. Rams, Piotr Czarnik +1
The Hubbard model is a longstanding problem in the theory of strongly correlated electrons and a very active one in the experiments with ultracold fermionic atoms. Motivated by cur…
The battle of clean and dirty qubits in the era of partial error correction
Daniel Bultrini, Samson Wang, Piotr Czarnik +4
When error correction becomes possible it will be necessary to dedicate a large number of physical qubits to each logical qubit. Error correction allows for deeper circuits to be r…
Improving the efficiency of learning-based error mitigation
Piotr Czarnik, Michael McKerns, Andrew T. Sornborger +1
Error mitigation will play an important role in practical applications of near-term noisy quantum computers. Current error mitigation methods typically concentrate on correction qu…
Can Error Mitigation Improve Trainability of Noisy Variational Quantum Algorithms?
Samson Wang, Piotr Czarnik, Andrew Arrasmith +3
Variational Quantum Algorithms (VQAs) are often viewed as the best hope for near-term quantum advantage. However, recent studies have shown that noise can severely limit the traina…
Unifying and benchmarking state-of-the-art quantum error mitigation techniques
Daniel Bultrini, Max Hunter Gordon, Piotr Czarnik +4
Error mitigation is an essential component of achieving a practical quantum advantage in the near term, and a number of different approaches have been proposed. In this work, we re…
Variational Quantum Eigensolver with Reduced Circuit Complexity
Yu Zhang, Lukasz Cincio, Christian F. A. Negre +6
The variational quantum eigensolver (VQE) is one of the most promising algorithms to find eigenvalues and eigenvectors of a given Hamiltonian on noisy intermediate-scale quantum (N…
Diagnosing Barren Plateaus with Tools from Quantum Optimal Control
Martin Larocca, Piotr Czarnik, Kunal Sharma +3
Variational Quantum Algorithms (VQAs) have received considerable attention due to their potential for achieving near-term quantum advantage. However, more work is needed to underst…
Qubit-efficient exponential suppression of errors
Piotr Czarnik, Andrew Arrasmith, Lukasz Cincio +1
Achieving a practical advantage with near-term quantum computers hinges on having effective methods to suppress errors. Recent breakthroughs have introduced methods capable of expo…
Tensor network study of the magnetization plateau in the Shastry-Sutherland model at finite temperature
Piotr Czarnik, Marek M. Rams, Philippe Corboz +1
The two-dimensional infinite projected entangled pair states tensor network is evolved in imaginary time with the full update (FU) algorithm to simulate the Shastry-Sutherland mode…
Effect of barren plateaus on gradient-free optimization
Andrew Arrasmith, M. Cerezo, Piotr Czarnik +2
Barren plateau landscapes correspond to gradients that vanish exponentially in the number of qubits. Such landscapes have been demonstrated for variational quantum algorithms and q…
Unified approach to data-driven quantum error mitigation
Angus Lowe, Max Hunter Gordon, Piotr Czarnik +3
Achieving near-term quantum advantage will require effective methods for mitigating hardware noise. Data-driven approaches to error mitigation are promising, with popular examples…
Error mitigation with Clifford quantum-circuit data
Piotr Czarnik, Andrew Arrasmith, Patrick J. Coles +1
Achieving near-term quantum advantage will require accurate estimation of quantum observables despite significant hardware noise. For this purpose, we propose a novel, scalable err…
Tensor network simulation of the Kitaev-Heisenberg model at finite temperature
Piotr Czarnik, Anna Francuz, Jacek Dziarmaga
We investigate the Kitaev-Heisenberg (KH) model at finite temperature using the exact environment full update (eeFU), introduced in Phys. Rev. B 99, 035115 (2019), which represents…
Finite correlation length scaling with infinite projected entangled pair states at finite temperature
Piotr Czarnik, Philippe Corboz
We study second order finite temperature phase transitions of the 2D quantum Ising and interacting honeycomb fermions models using infinite projected entangled pair states (iPEPS).…
Time Evolution of an Infinite Projected Entangled Pair State: an Efficient Algorithm
Piotr Czarnik, Jacek Dziarmaga, Philippe Corboz
An infinite projected entangled pair state (iPEPS) is a tensor network ansatz to represent a quantum state on an infinite 2D lattice whose accuracy is controlled by the bond dimens…
Time Evolution of an Infinite Projected Entangled Pair State: an Algorithm from First Principles
Piotr Czarnik, Jacek Dziarmaga
A typical quantum state obeying the area law for entanglement on an infinite 2D lattice can be represented by a tensor network ansatz -- known as an infinite projected entangled pa…
Finite correlation length scaling with infinite projected entangled-pair states
Philippe Corboz, Piotr Czarnik, Geert Kapteijns +1
We show how to accurately study 2D quantum critical phenomena using infinite projected entangled-pair states (iPEPS). We identify the presence of a finite correlation length in the…
Precise extrapolation of the correlation function asymptotics in uniform tensor network states with application to the Bose-Hubbard and XXZ models
Marek M. Rams, Piotr Czarnik, Lukasz Cincio
We analyze the problem of extracting the correlation length from infinite matrix product states (MPS) and corner transfer matrix (CTM) simulations. When the correlation length is c…