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Related papers: Feedback Policies for Measurement-based Quantum St…

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We propose an all-electronic technique to manipulate and control interacting quantum systems by unitary single-jump feedback conditioned on the outcome of a capacitively coupled electrometer and in particular a single-electron transistor.…

Mesoscale and Nanoscale Physics · Physics 2013-01-07 Gerold Kiesslich , Clive Emary , Gernot Schaller , Tobias Brandes

This work introduces a self-learning protocol that incorporates measurement and feedback into variational quantum circuits for efficient quantum state preparation. By combining projective measurements with conditional feedback, the protocol…

Quantum Physics · Physics 2025-07-16 Daniel Alcalde Puente , Matteo Rizzi

Quantum mechanical systems exhibit an inherently probabilistic nature upon measurement which excludes in principle the singular direct observability continual case. Quantum theory of time continuous measurements and quantum prediction…

Mathematical Physics · Physics 2007-05-23 V. P. Belavkin

We consider the problem of frequency estimation for a single bosonic field evolving under a squeezing Hamiltonian and continuously monitored via homodyne detection. In particular, we exploit reinforcement learning techniques to devise…

Quantum Physics · Physics 2022-04-19 Alessio Fallani , Matteo A. C. Rossi , Dario Tamascelli , Marco G. Genoni

Quantum control is concerned with active manipulation of physical and chemical processes on the atomic and molecular scale. This work presents a perspective of progress in the field of control over quantum phenomena, tracing the evolution…

Quantum Physics · Physics 2010-07-20 Constantin Brif , Raj Chakrabarti , Herschel Rabitz

Feedback-based quantum algorithms have recently emerged as potential methods for approximating the ground states of Hamiltonians. One such algorithm, the feedback-based algorithm for quantum optimization (FALQON), is specifically designed…

Quantum Physics · Physics 2025-08-18 Salahuddin Abdul Rahman , Özkan Karabacak , Rafal Wisniewski

In the Markov decision process model, policies are usually evaluated by expected cumulative rewards. As this decision criterion is not always suitable, we propose in this paper an algorithm for computing a policy optimal for the quantile…

Artificial Intelligence · Computer Science 2016-12-02 Hugo Gilbert , Paul Weng , Yan Xu

A quantum system may be purified, i.e., projected into a pure state, faster if one applies feedback operations during the measurement process. However existing results suggest that such an enhancement is only possible when the measurement…

Quantum Physics · Physics 2020-08-19 Yuxiao Jiang , Xiyue Wang , Leigh Martin , K. Birgitta Whaley

This article provides a novel continuous-time state feedback control strategy to stabilize an eigenstate of the Hermitian measurement operator of a two-level quantum system. In open loop, such system converges stochastically to one of the…

Quantum Physics · Physics 2019-04-11 Gerardo Cardona , Alain Sarlette , Pierre Rouchon

We show that in the regime in which feedback control is most effective -- when measurements are relatively efficient, and feedback is relatively strong -- then, in the absence of any sharp inhomogeneity in the noise, it is always best to…

Quantum Physics · Physics 2009-11-13 Kurt Jacobs , Austin P. Lund

We present and discuss different protocols for preparing an arbitrary quantum state of a qubit using only a restricted set of measurements, with no unitary operations at all. We show that an arbitrary state can indeed be prepared, provided…

Quantum Physics · Physics 2015-03-17 S. Ashhab , Franco Nori

Obtaining reliable state preparation protocols is a key step towards practical implementation of many quantum technologies, and one of the main tasks in quantum control. In this work, different reinforcement learning approaches are used to…

Quantum Physics · Physics 2024-09-04 Manuel Guatto , Gian Antonio Susto , Francesco Ticozzi

We present an optimal control-based strategy to enhance the estimation of impulse-like disturbances in continuously monitored linear classical and quantum systems by exploiting non-equilibrium states. Using optimal estimation techniques for…

Quantum Physics · Physics 2026-05-13 Kaspar Schmerling , Andreas Kugi , Andreas Deutschmann-Olek

This thesis addresses the problem of developing a quantum counter-part of the well established classical theory of control. We dwell on the fundamental fact that quantum states are generally not perfectly distinguishable, and quantum…

Quantum Physics · Physics 2009-08-21 Paulo E. M. F. Mendonca

We study a feedback scheme to stabilize an arbitrary photon number state in a microwave cavity. The quantum non-demolition measurement of the cavity state allows a non-deterministic preparation of Fock states. Here, by the mean of a…

Optimization and Control · Mathematics 2010-11-11 Hadis Amini , Mazyar Mirrahimi , Pierre Rouchon

To control a quantum system via feedback, we generally have two options in choosing control scheme. One is the coherent feedback, which feeds the output field of the system, through a fully quantum device, back to manipulate the system…

Quantum Physics · Physics 2014-11-19 Naoki Yamamoto

We propose several parametrization-free solutions to the problem of quantum state reduction control by means of continuous measurement and smooth quantum feedback. In particular, we design a feedback law for which almost global stochastic…

Quantum Physics · Physics 2007-05-23 Claudio Altafini , Francesco Ticozzi

We describe a scheme for quantum error correction that employs feedback and weak measurement rather than the standard tools of projective measurement and fast controlled unitary gates. The advantage of this scheme over previous protocols…

Quantum Physics · Physics 2009-11-10 Mohan Sarovar , Charlene Ahn , Kurt Jacobs , Gerard J. Milburn

The paper provides a new approach to the determination of a single state value for stochastic output feedback problems using paradigms from Model Predictive Control, particularly the distinction between open-loop and closed-loop control and…

Optimization and Control · Mathematics 2023-03-03 Mohammad S. Ramadan , Robert R. Bitmead , Ke Huang

We present a model to realize quantum feedback control of continuous variable entanglement. It consists of two interacting bosonic modes subject to amplitude damping and achieving entangled Gaussian steady state. The possibility to greatly…

Quantum Physics · Physics 2009-11-11 Stefano Mancini