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Model robustness for feedback stabilization of open quantum systems https://lnkd.in/eG8iBzRU Weichao Liang, Nina Amini. Model robustness for feedback stabilization of open quantum systems. Automatica, In press https://lnkd.in/exDVzW4x https://lnkd.in/e7Dm5QP5 Abstract: This paper builds upon and expands the findings presented in Liang et al. (2021). Our focus lies in scenarios where initial states and model parameters remain unknown. In contrast to prior research, we consider multiple measurement channels, addressing the challenge of global exponential stabilization towards a chosen target subspace. Under quantum non-demolition conditions, our analysis establishes essential tools for achieving feedback stabilization. Furthermore, we explore the utilization of a simplified filter as a viable alternative to full state estimator. While the effectiveness of this simplified filter was numerically examined in Cardona et al. (2020), our paper offers a comprehensive proof of its applicability in feedback stabilization. Furthermore, our analysis may serve as an inspiration for demonstrating the validation of the robust feedback stabilization through generic approximate filters.

Model robustness for feedback stabilization of open quantum systems Weichao Liang & Nina Hadis Amini https://lnkd.in/eG8iBzRU Q-COAST ANR projet "Estimation and control of open quantum systems" : https://lnkd.in/e7G8fVKX Abstrat: This paper generalizes the results in [30] concerning feedback stabilization of target states for N-level quantum angular momentum systems undergoing quantum non-demolition measurements (QND) in absence of the knowledge about initial states and parameters. Here we consider multiple measurement operators and study the stabilization toward a chosen target subspace which is a common eigenspace of measurement operators. Under the QND conditions, we show that this analysis provides necessary tools to ensure feedback stabilization based on a simplified filter whose state is a N-dimensional vector. A numerical analysis has been proposed in [18]. This paper provides a complete proof for the use of a simplified filter in feedback stabilization. This has important practical use as the dimension of quantum systems is usually high. This paper opens the way toward a complete proof concerning the robustness of a stabilizing feedback with respect to approximate filters, which is lacking.

A nice introductory lecture notes on quantum algorithms in open quantum systems (read here: https://lnkd.in/dJyx2uQ6)

#qecarxiv Smallest quantum codes for amplitude damping noise [https://lnkd.in/gneYRy-n] This paper introduces the smallest known quantum error-correcting codes designed specifically to protect against amplitude damping noise, which commonly arises in quantum systems like superconducting qubits and optical systems. The authors construct minimal codes capable of correcting single amplitude-damping errors with fewer qubits than previously known codes, demonstrating their practical applicability for near-term quantum devices where qubit resources are limited.

This article introduced me to the concept of the quantum singular value transformation, or QSVT https://lnkd.in/eBZEYTTA

So, what does this mean for the quantum computing industry? MEQ-enhanced materials can offer more stable environments for qubits, reduce error rates, and improve computational performance. We're talking about scalable quantum systems and enhanced quantum coherence—key factors in making quantum computing a reality.

Dissipation is a phenomenon that destroys quantum entanglement, a necessary resource in quantum algorithms. However, today we discuss how engineered dissipation can in fact aid a quantum processor by steering it into a desired entangled state → https://goo.gle/3UcpX1R

scientists from the University of Turku in Finland and the University of Science and Technology of China developed a new quantum teleportation method that overcomes this noise and achieves a high rate of success. The key to their success is the use of multipartite hybrid entanglement, which is like entangling the qubits

Lecture 7: Elements of Quantum Circuits; two-qubit operations. Entanglement. https://lnkd.in/ehgG3yAD

Welcome to a new course on advanced Quantum Algorithms. Here I plan to cover algorithms on Hamiltonian Simulation , Quantum Walks , Generalized Quantum Fourier Transform, and Quantum Adiabatic Algorithms. The first lecture of the course is available here :- https://lnkd.in/gSmhhbqU. Here we review Quantum Circuits and also review Quantum Fourier Transform with a recursive approach. The main references for the course mainly consist of the notes by Andrew Childs:- https://lnkd.in/gXtRESz4 We will also discuss some research papers in the area as well. Pre-requisites for the course include knowledge of Quantum Circuits and some basic Quantum algorithms such as Deutch Josza and Bernstein Vazirani.