225 citations · 1.2k across the 31 of their papers we have counts for
30 papers · 1 filter
Robustness of quantum algorithms: Worst-case fidelity bounds and implications for design
Julian Berberich, Tobias Fellner, Robert L. Kosut +1
Errors occurring on noisy hardware pose a key challenge to reliable quantum computing. Existing techniques such as error correction, mitigation, or suppression typically separate t…
A Fundamental Bound for Robust Quantum Gate Control
Robert L. Kosut, Daniel A. Lidar, Herschel Rabitz
We derive a universal performance limit for coherent quantum control in the presence of modeled and unmodeled uncertainties. For any target unitary that is implementable in the…
Hamiltonian Switching Control of Noisy Bipartite Qubit Systems
Zhibo Yang, Robert L. Kosut, K. Birgitta Whaley
We develop a Hamiltonian switching ansatz for bipartite control that is inspired by the Quantum Approximate Optimization Algorithm (QAOA), to mitigate environmental noise on qubits…
Robust Quantum Control: Analysis & Synthesis via Averaging
Robert L. Kosut, Gaurav Bhole, Herschel Rabitz
An approach is presented for robustness analysis and quantum (unitary) control synthesis based on the classic method of averaging. The result is a multicriterion optimization compe…
From pulses to circuits and back again: A quantum optimal control perspective on variational quantum algorithms
Alicia B. Magann, Christian Arenz, Matthew D. Grace +5
The last decade has witnessed remarkable progress in the development of quantum technologies. Although fault-tolerant devices likely remain years away, the noisy intermediate-scale…
Quantum System Compression: A Hamiltonian Guided Walk Through Hilbert Space
Robert L. Kosut, Tak-San Ho, Herschel Rabitz
We present a systematic study of quantum system compression for the evolution of generic many-body problems. The necessary numerical simulations of such systems are seriously hinde…
Robust Control Optimization for Quantum Approximate Optimization Algorithm
Yulong Dong, Xiang Meng, Lin Lin +2
Quantum variational algorithms have garnered significant interest recently, due to their feasibility of being implemented and tested on noisy intermediate scale quantum (NISQ) devi…
Minimal Time Robust Control for Two Superconducting Qubits
Niril George, Joseph L. Allen, Robert Kosut +1
High-fidelity quantum gates are crucial for achieving fault-tolerant quantum computing; however, decoherence significantly reduces gate fidelities during long operation times. Alth…
Quantum Control Landscape of Bipartite Systems
Robert L. Kosut, Christian Arenz, Herschel Rabitz
The control landscape of a quantum system interacting with another quantum system is studied. Only system is accessible through time dependent controls, while system B…
Optimal control of two qubits via a single cavity drive in circuit quantum electrodynamics
Joseph L. Allen, Robert Kosut, Jaewoo Joo +2
Optimization of the fidelity of control operations is of critical importance in the pursuit of fault-tolerant quantum computation. We apply optimal control techniques to demonstrat…
Quantum Tomography Protocols with Positivity are Compressed Sensing Protocols
Amir Kalev, Robert L. Kosut, Ivan H. Deutsch
Characterizing complex quantum systems is a vital task in quantum information science. Quantum tomography, the standard tool used for this purpose, uses a well-designed measurement…
Compressed sensing quantum process tomography for superconducting quantum gates
Andrey V. Rodionov, Andrzej Veitia, R. Barends +6
We apply the method of compressed sensing (CS) quantum process tomography (QPT) to characterize quantum gates based on superconducting Xmon and phase qubits. Using experimental dat…
Robust control of quantum gates via sequential convex programming
Robert L. Kosut, Matthew D. Grace, Constantin Brif
Resource tradeoffs can often be established by solving an appropriate robust optimization problem for a variety of scenarios involving constraints on optimization variables and unc…
Efficient estimation of nearly sparse many-body quantum Hamiltonians
A. Shabani, M. Mohseni, S. Lloyd +2
We develop an efficient and robust approach to Hamiltonian identification for multipartite quantum systems based on the method of compressed sensing. This work demonstrates that wi…
Simplified Quantum Process Tomography
M. P. A. Branderhorst, J. Nunn, I. A. Walmsley +1
We propose and evaluate experimentally an approach to quantum process tomography that completely removes the scaling problem plaguing the standard approach. The key to this simplif…
Efficient measurement of quantum dynamics via compressive sensing
A. Shabani, R. L. Kosut, M. Mohseni +5
The resources required to characterise the dynamics of engineered quantum systems-such as quantum computers and quantum sensors-grow exponentially with system size. Here we adapt t…
Environment-invariant measure of distance between evolutions of an open quantum system
Matthew D. Grace, Jason Dominy, Robert L. Kosut +2
The problem of quantifying the difference between evolutions of an open quantum system (in particular, between the actual evolution of an open system and the ideal target operation…
Optimal quantum multi-parameter estimation and application to dipole- and exchange-coupled qubits
Kevin C. Young, Mohan Sarovar, Robert Kosut +1
We consider the problem of quantum multi-parameter estimation with experimental constraints and formulate the solution in terms of a convex optimization. Specifically, we outline a…
Quantum Process Tomography via L1-norm Minimization
Robert L. Kosut
For an initially well designed but imperfect quantum information system, the process matrix is almost sparse in an appropriate basis. Existing theory and associated computational m…
Channel-Optimized Quantum Error Correction
Soraya Taghavi, Robert L. Kosut, Daniel A. Lidar
We develop a theory for finding quantum error correction (QEC) procedures which are optimized for given noise channels. Our theory accounts for uncertainties in the noise channel,…
Quantum Metrology Subject to Instrumentation Constraints
Robert L. Kosut
Maximizing the precision in estimating parameters in a quantum system subject to instrumentation constraints is cast as a convex optimization problem. We account for prior knowledg…
Fidelity of optimally controlled quantum gates with randomly coupled multiparticle environments
Matthew D. Grace, Constantin Brif, Herschel Rabitz +3
This work studies the feasibility of optimal control of high-fidelity quantum gates in a model of interacting two-level particles. One particle (the qubit) serves as the quantum in…
Robust Quantum Error Correction via Convex Optimization
R. L. Kosut, A. Shabani, D. A. Lidar
We present a semidefinite program optimization approach to quantum error correction that yields codes and recovery procedures that are robust against significant variations in the…
Optimal control of quantum gates and suppression of decoherence in a system of interacting two-level particles
Matthew Grace, Constantin Brif, Herschel Rabitz +3
Methods of optimal control are applied to a model system of interacting two-level particles (e.g., spin-half atomic nuclei or electrons or two-level atoms) to produce high-fidelity…