Coherent feedback control in quantum transport

Emary, Clive; Gough, John E.

doi:10.1103/physrevb.90.205436

Cited by 14 publications

(35 citation statements)

References 62 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Recent technological progress has enabled advances in superconducting circuits both theoretically [177] and experimentally [178,179]. A problem that is starting to attract attention is feedback control in quantum transport [180]. In summary, the objective is to understand how the current quantum control techniques developed for quantum optical systems can be applied to hybrid systems involving quantum dots, superconducting qubits and opto-mechanical resonators.…”

Section: Mid-term Prospects: Goals and Challengesmentioning

confidence: 99%

Training Schrödinger’s cat: quantum optimal control

et al. 2015

View full text Add to dashboard Cite

Abstract. It is control that turns scientific knowledge into useful technology: in physics and engineering it provides a systematic way for driving a dynamical system from a given initial state into a desired target state with minimized expenditure of energy and resources. As one of the cornerstones for enabling quantum technologies, optimal quantum control keeps evolving and expanding into areas as diverse as quantumenhanced sensing, manipulation of single spins, photons, or atoms, optical spectroscopy, photochemistry, magnetic resonance (spectroscopy as well as medical imaging), quantum information processing and quantum simulation. In this communication, state-of-the-art quantum control techniques are reviewed and put into perspective by a consortium of experts in optimal control theory and applications to spectroscopy, imaging, as well as quantum dynamics of closed and open systems. We address key challenges and sketch a roadmap for future developments. ForewordThe authors of this paper represent the QUAINT consortium, a European Coordination Action on Optimal Control of Quantum Systems, funded by the European Commission Framework Programme 7, Future Emerging Technologies FET-OPEN programme and the Virtual Facility for Quantum Control (VF-QC). This consortium has considerable expertise in optimal control theory and its applications to quantum systems, both in existing areas, such as spectroscopy and imaging, and in emerging quantum technologies, such as quantum information processing, quantum communication, quantum simulation a e-mail: fwm@lusi.uni-sb.de and quantum sensing. The list of challenges for quantum control has been gathered by a broad poll of leading researchers across the communities of general and mathematical control theory, atomic, molecular-, and chemical physics, electron and nuclear magnetic resonance spectroscopy, as well as medical imaging, quantum information, communication and simulation. 144 experts in these fields have provided feedback and specific input on the state of the art, mid-term and long-term goals. Those have been summarized in this document, which can be viewed as a perspectives paper, providing a roadmap for the future development of quantum control. Because such an endeavour can hardly ever be complete (there are many additional areas of quantum control applications, such as spintronics, nano-optomechanical technologies etc.), this roadmap

show abstract

Section: Mid-term Prospects: Goals and Challengesmentioning

confidence: 99%

Training Schrödinger’s cat: quantum optimal control

et al. 2015

View full text Add to dashboard Cite

show abstract

“…[5,28,29]. However, the only type currently proposed for quantum transport [30,31] is the quantum feedback network [29,[32][33][34][35][36][37], and this is the work we describe here.…”

Section: Coherent Controlmentioning

confidence: 99%

“…[30] assumes that the system is strongly coupled to the leads, that the motion of the electrons through system and controller is phase coherent and that electron-electron interactions can be neglected. In this limit, transport can be described by Landauer-Büttiker theory [38].…”

Section: Quantum Feedback Networkmentioning

confidence: 99%

“…(1.16), Ref. [30] studied the optimisation of the conductance of chaotic quantum dots. The dots were modeled with 4N × 4N scattering matrices taken from random matrix theory [39].…”

Section: Conductance Optimisationmentioning

confidence: 99%

“…Ref. [30] considered that the system to controlled was a four-terminal device (see Fig. 1.3), whose scattering matrix could be written in block form as…”

Section: Quantum Feedback Networkmentioning

confidence: 99%

See 2 more Smart Citations

Feedback Control in Quantum Transport

Emary

2016

Understanding Complex Systems

Self Cite

View full text Add to dashboard Cite

Abstract. Quantum transport is the study of the motion of electrons through nano-scale structures small enough that quantum effects are important. In this contribution I review recent theoretical proposals to use the techniques of quantum feedback control to manipulate the properties of electron flows and states in quantum-transport devices. Quantum control strategies can be grouped into two broad classes: measurement-based control and coherent control, and both are covered here. I discuss how measurement-based techniques are capable of producing a range of effects, such as noise suppression, stabilisation of nonequillibrium quantum states and the realisation of a nano-electronic Maxwell's demon. I also describe recent results on coherent transport control and its relation to quantum networks. IntroductionFeedback control of quantum mechanical systems is a rapidly emerging topic [1,2], developed most fully in the field of quantum optics [3]. Only recently have these ideas been extended to quantum transport, a field which looks to understand and control the motion of electrons through structures on the nano-scale [4]. The aim of this contribution is to review these recent developments.Broadly speaking, quantum feedback strategies may usefully be classified into two types:• Measurement-based control, where the quantum system is subject to measurements, the classical information from which forms the basis of the feedback loop; • Coherent control, where the system, the controller and their interconnections are phase coherent such that the information flow in the feedback loop is of quantum information [5].Mirroring the situation in optics, most of the work to-date on feedback in quantum transport has been within the measurement-based paradigm. In Sec. 1.2 here, we discuss a number of different measurement-based schemes

show abstract

A feedback scheme for control of single electron transport

Brandes

2017

Physica Status Solidi (b)

View full text Add to dashboard Cite

We revise a feedback control scheme for single electron transport. It is based on the idea of an adaptive modulation of the system parameters (such as tunnel rates) during the observation of the full counting statistics. This can be done via an iterative, step‐wise modulation, or in a continuous manner. We compare these two procedures and discuss an extension of the previously used linear feedback protocol to the non‐linear case. This involves an exponential dependence of tunnel rates on the differences n−I0t, where n is the number of electrons transferred after time t and I0 the stationary target current. The feedback freezes the full counting statistics into a stationary distribution that we derive and analyze using a Fokker–Planck equation.

show abstract

Coherent feedback control in quantum transport

Cited by 14 publications

References 62 publications

Training Schrödinger’s cat: quantum optimal control

Training Schrödinger’s cat: quantum optimal control

Feedback Control in Quantum Transport

A feedback scheme for control of single electron transport

Contact Info

Product

Resources

About