Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:1304.4710 · New Journal of Physics

Quantum information processing with trapped electrons and superconducting electronics

Nikos Daniilidis, Dylan J Gorman, Lin Tian, Hartmut Häffner

Published Jul 5, 2013• 29 citations
arXivHTMLPDF

Abstract

We describe a parametric frequency conversion scheme for trapped charged particles, which enables a coherent interface between atomic and solid-state quantum systems. The scheme uses geometric nonlinearities of the potential of coupling electrodes near a trapped particle, and can be implemented using standard charged-particle traps. Our scheme does not rely on actively driven solid-state devices, and is hence largely immune to noise in such devices. We present a toolbox which can be used to build electron-based quantum information processing platforms, as well as quantum hybrid platforms using trapped electrons and superconducting electronics.

DOI
10.1088/1367-2630/15/7/073017

Related papers

Hybrid quantum systems with trapped charged particles

Shlomi Kotler, Raymond W. Simmonds, Dietrich G. Leibfried +1 more

Trapped charged particles have been at the forefront of quantum information processing (QIP) for a few decades now, with deterministic two-qubit logic gates reaching record fidelities of $99.9%$ and single-qubit operations of much higher fidelity. In a hybrid system involving trapped charges, quantum degrees of freedom of macroscopic objects such as bulk acoustic resonators, superconducting circuits, or nanomechanical membranes, couple to the trapped charges and ideally inherit the coherent properties of the charges. The hybrid system therefore implements a ``quantum transducer,'' where the quantum reality (i.e., superpositions and entanglement) of small objects is extended to include the larger object. Although a hybrid quantum system with trapped charges could be valuable both for fundamental research and for QIP applications, no such system exists today. Here we study theoretically the possibilities of coupling the quantum-mechanical motion of a trapped charged particle (e.g., an ion or electron) to the quantum degrees of freedom of superconducting devices, nanomechanical resonators, and quartz bulk acoustic wave resonators. For each case, we estimate the coupling rate between the charged particle and its macroscopic counterpart and compare it to the decoherence rate, i.e., the rate at which quantum superposition decays. A hybrid system can only be considered quantum if the coupling rate significantly exceeds all decoherence rates. Our approach is to examine specific examples by using parameters that are experimentally attainable in the foreseeable future. We conclude that hybrid quantum systems involving a single atomic ion are unfavorable compared with the use of a single electron because the coupling rates between the ion and its counterpart are slower than the expected decoherence rates. A system based on trapped electrons, on the other hand, might have coupling rates that significantly exceed decoherence rates. Moreover, it might have appealing properties such as fast entangling gates, long coherence, and flexible topology that is fully electronic in nature. Realizing such a system, however, is technologically challenging because it requires accommodating both a trapping technology and superconducting circuitry in a compatible manner. We review some of the challenges involved, such as the required trap parameters, electron sources, electrical circuitry, and cooling schemes in order to promote further investigations towards the realization of such a hybrid system.

arXiv:1608.02677•Physical Review A•Feb 21, 2017•43 citations

Issues using equivalent circuit elements to describe trapped charged particles

Noah Van Horne, Manas Mukherjee

Trapped charged particles are among the leading qubit candidates for quantum computing technologies. However, our ability to interconnect arrays of particles in different traps is a significant hurdle in scaling trapped charged particle quantum computing. One approach explored to overcome this problem is to use a solid state conducting wire to mediate the Coulomb interaction between particles in different traps. Additionally, there is strong interest in interfacing trapped charged particle qubits with solid state superconducting qubits to develop hybrid systems which benefit from the complementary strengths of the two technologies. For studies related to these fields, a trapped charged particle inducing charge on a conductor has long been modeled using equivalent circuit elements. The equivalent circuit element approach is popular partly due to the appeal of a model for analyzing systems using simple electronic components. As a result, a body of theoretical work is founded on this approach. However, careful consideration of the model leads to inconsistencies. We show that this suggests many studies based on the model should be reviewed. Our result removes a potential road-block for future studies aiming to use conductors to connect independent arrays of charged particles, or to interface charged particles with solid-state qubit technologies. In addition, for the specific case of two trapped charges interacting via a conducting coupling system, we introduce an alternative way to use linear relationships, which reproduces results from other works that are not based on the circuit-element model. This method may be useful in trouble-shooting real experimental designs and assessing the accuracy of different theoretical models.

arXiv:2008.07128•Aug 17, 2020•0 citations

Quantum Interfaces Between Atomic and Solid-State Systems

Nikos Daniilidis, Hartmut Häffner

We discuss interfacing trapped atomic systems with solid-state systems such as superconducting Josephson-junction devices or nanomechanical oscillators. Such hybrid quantum systems could ease scalable quantum information processing and yield novel and profound insight into the quantum mechanics of macroscopic quantum many-body systems. We review the relevant interactions and illuminate the role of the vastly differing impedance of atomic and solid-state systems. We give some basic guidelines toward combining quantum systems, and finally, discuss some concrete proposals to interface atomic with solid-state systems.

Annual Review of Condensed Matter Physics•Jan 9, 2013•25 citations

Scalable Ion Trap Quantum Computing without Moving Ions

Lin Tian, R. Blatt, P. Zoller

A hybrid quantum computing scheme is studied where the hybrid qubit is made of an ion trap qubit serving as the information storage and a solid-state charge qubit serving as the quantum processor, connected by a superconducting cavity. In this paper, we extend our previous work [1] and study the decoherence, coupling and scalability of the hybrid system. We present our calculations of the decoherence of the coupled ion - charge system due to the charge fluctuations in the solid-state system and the dissipation of the superconducting cavity under laser radiation. A gate scheme that exploits rapid state flips of the charge qubit to reduce decoherence by the charge noise is designed. We also study a superconducting switch that is inserted between the cavity and the charge qubit and provides tunable coupling between the qubits. The scalability of the hybrid scheme is discussed together with several potential experimental obstacles in realizing this scheme.

•Dec 23, 2004•9 citations

How to couple trapped ions to superconducting resonators: towards hybrid quantum devices

Sönke Möller

In this dissertation, we present work on a quantum hybrid device comprising of a trapped calcium atom and a superconducting LC resonator. This hybrid device is a first step towards building a hybrid quantum computer that can take advantage of the different properties of atomic and superconducting quantum systems and combine the best characteristics of both. We model a trapped ion as an LC circuit and calculate its coupling to a mode of an LC resonator. Further, we optimize the trap geometry and placement of coupling electrodes to increase the coupling. We also outline the manufacturing process and simulation of the trapping potentials for the surface traps used in this work. Finally, we report on initial experiments coupling a trapped ion to a resonant mode of the LC resonator, increasing the heating rate to 220 phonons/ms on resonance versus 0.5 phonons/ms without additional heating from the resonator. The ratio of the heating rates for the two secular frequencies of the ion confrm our simulated coupling rates.

•Jan 1, 2016•1 citation

Polar molecules near superconducting resonators: a coherent, all-electrical, molecule-mesoscopic interface

Axel André, David P. DeMille, John M. Doyle +5 more

The challenge of building a scalable quantum processor requires consolidation of the conflicting requirements of achieving coherent control and preservation of quantum coherence in a large scale quantum system. Moreover, the system should be compatible with miniaturization and integration of quantum circuits. Mesoscopic solid state systems such as superconducting islands and quantum dots feature robust control techniques using local electrical signals and self-evident scaling based on advances in fabrication; however, in general the quantum states of solid state devices tend to decohere rapidly. In contrast, quantum optical systems based on trapped ions and neutral atoms exhibit dramatically better coherence properties, while miniaturization of atomic and molecular systems, and their integration with mesoscopic electrical circuits, remains an important challenge. Below we describe methods for the integration of a single particle system -- an isolated polar molecule -- with mesoscopic solid state devices in a way that produces robust, coherent, quantum-level control. The methods described include the trapping, cooling, detection, coherent manipulation and quantum coupling of isolated polar molecules at sub-micron dimensions near cryogenic stripline microwave resonators. We show that electrostatically trapped polar molecules can exhibit strong confinement and fast, purely electrical gate control. Furthermore, the effect of electrical noise sources, a key issue in quantum information processing, can be suppressed to very low levels via appropriate preparation and manipulation of the polar molecules. Our setup provides a scalable cavity QED-type quantum computer architecture, where entanglement of distant qubits stored in long-lived rotational molecular states is achieved via exchange of microwave photons.

arXiv:quant-ph/0605201•May 23, 2006•5 citations
We describe a parametric frequency conversion scheme for trapped charged particles, which enables a coherent interface between atomic and solid-state quantum systems. The scheme uses geometric nonlinearities of the potential of coupling electrodes near a trapped particle, and can be implemented using standard charged-particle traps. Our scheme does not rely on actively driven solid-state devices, and is hence largely immune to noise in such devices. We present a toolbox which can be used to build electron-based quantum information processing platforms, as well as quantum hybrid platforms using trapped electrons and superconducting electronics.
Trapped charged particles have been at the forefront of quantum information processing (QIP) for a few decades now, with deterministic two-qubit logic gates reaching record fidelities of 99.999.9%99.9 and single-qubit operations of much higher fidelity. In a hybrid system involving trapped charges, quantum degrees of freedom of macroscopic objects such as bulk acoustic resonators, superconducting circuits, or nanomechanical membranes, couple to the trapped charges and ideally inherit the coherent properties of the charges. The hybrid system therefore implements a ``quantum transducer,'' where the quantum reality (i.e., superpositions and entanglement) of small objects is extended to include the larger object. Although a hybrid quantum system with trapped charges could be valuable both for fundamental research and for QIP applications, no such system exists today. Here we study theoretically the possibilities of coupling the quantum-mechanical motion of a trapped charged particle (e.g., an ion or electron) to the quantum degrees of freedom of superconducting devices, nanomechanical resonators, and quartz bulk acoustic wave resonators. For each case, we estimate the coupling rate between the charged particle and its macroscopic counterpart and compare it to the decoherence rate, i.e., the rate at which quantum superposition decays. A hybrid system can only be considered quantum if the coupling rate significantly exceeds all decoherence rates. Our approach is to examine specific examples by using parameters that are experimentally attainable in the foreseeable future. We conclude that hybrid quantum systems involving a single atomic ion are unfavorable compared with the use of a single electron because the coupling rates between the ion and its counterpart are slower than the expected decoherence rates. A system based on trapped electrons, on the other hand, might have coupling rates that significantly exceed decoherence rates. Moreover, it might have appealing properties such as fast entangling gates, long coherence, and flexible topology that is fully electronic in nature. Realizing such a system, however, is technologically challenging because it requires accommodating both a trapping technology and superconducting circuitry in a compatible manner. We review some of the challenges involved, such as the required trap parameters, electron sources, electrical circuitry, and cooling schemes in order to promote further investigations towards the realization of such a hybrid system.
Trapped charged particles are among the leading qubit candidates for quantum computing technologies. However, our ability to interconnect arrays of particles in different traps is a significant hurdle in scaling trapped charged particle quantum computing. One approach explored to overcome this problem is to use a solid state conducting wire to mediate the Coulomb interaction between particles in different traps. Additionally, there is strong interest in interfacing trapped charged particle qubits with solid state superconducting qubits to develop hybrid systems which benefit from the complementary strengths of the two technologies. For studies related to these fields, a trapped charged particle inducing charge on a conductor has long been modeled using equivalent circuit elements. The equivalent circuit element approach is popular partly due to the appeal of a model for analyzing systems using simple electronic components. As a result, a body of theoretical work is founded on this approach. However, careful consideration of the model leads to inconsistencies. We show that this suggests many studies based on the model should be reviewed. Our result removes a potential road-block for future studies aiming to use conductors to connect independent arrays of charged particles, or to interface charged particles with solid-state qubit technologies. In addition, for the specific case of two trapped charges interacting via a conducting coupling system, we introduce an alternative way to use linear relationships, which reproduces results from other works that are not based on the circuit-element model. This method may be useful in trouble-shooting real experimental designs and assessing the accuracy of different theoretical models.
We discuss interfacing trapped atomic systems with solid-state systems such as superconducting Josephson-junction devices or nanomechanical oscillators. Such hybrid quantum systems could ease scalable quantum information processing and yield novel and profound insight into the quantum mechanics of macroscopic quantum many-body systems. We review the relevant interactions and illuminate the role of the vastly differing impedance of atomic and solid-state systems. We give some basic guidelines toward combining quantum systems, and finally, discuss some concrete proposals to interface atomic with solid-state systems.
A hybrid quantum computing scheme is studied where the hybrid qubit is made of an ion trap qubit serving as the information storage and a solid-state charge qubit serving as the quantum processor, connected by a superconducting cavity. In this paper, we extend our previous work [1] and study the decoherence, coupling and scalability of the hybrid system. We present our calculations of the decoherence of the coupled ion - charge system due to the charge fluctuations in the solid-state system and the dissipation of the superconducting cavity under laser radiation. A gate scheme that exploits rapid state flips of the charge qubit to reduce decoherence by the charge noise is designed. We also study a superconducting switch that is inserted between the cavity and the charge qubit and provides tunable coupling between the qubits. The scalability of the hybrid scheme is discussed together with several potential experimental obstacles in realizing this scheme.
In this dissertation, we present work on a quantum hybrid device comprising of a trapped calcium atom and a superconducting LC resonator. This hybrid device is a first step towards building a hybrid quantum computer that can take advantage of the different properties of atomic and superconducting quantum systems and combine the best characteristics of both. We model a trapped ion as an LC circuit and calculate its coupling to a mode of an LC resonator. Further, we optimize the trap geometry and placement of coupling electrodes to increase the coupling. We also outline the manufacturing process and simulation of the trapping potentials for the surface traps used in this work. Finally, we report on initial experiments coupling a trapped ion to a resonant mode of the LC resonator, increasing the heating rate to 220 phonons/ms on resonance versus 0.5 phonons/ms without additional heating from the resonator. The ratio of the heating rates for the two secular frequencies of the ion confrm our simulated coupling rates.
The challenge of building a scalable quantum processor requires consolidation of the conflicting requirements of achieving coherent control and preservation of quantum coherence in a large scale quantum system. Moreover, the system should be compatible with miniaturization and integration of quantum circuits. Mesoscopic solid state systems such as superconducting islands and quantum dots feature robust control techniques using local electrical signals and self-evident scaling based on advances in fabrication; however, in general the quantum states of solid state devices tend to decohere rapidly. In contrast, quantum optical systems based on trapped ions and neutral atoms exhibit dramatically better coherence properties, while miniaturization of atomic and molecular systems, and their integration with mesoscopic electrical circuits, remains an important challenge. Below we describe methods for the integration of a single particle system -- an isolated polar molecule -- with mesoscopic solid state devices in a way that produces robust, coherent, quantum-level control. The methods described include the trapping, cooling, detection, coherent manipulation and quantum coupling of isolated polar molecules at sub-micron dimensions near cryogenic stripline microwave resonators. We show that electrostatically trapped polar molecules can exhibit strong confinement and fast, purely electrical gate control. Furthermore, the effect of electrical noise sources, a key issue in quantum information processing, can be suppressed to very low levels via appropriate preparation and manipulation of the polar molecules. Our setup provides a scalable cavity QED-type quantum computer architecture, where entanglement of distant qubits stored in long-lived rotational molecular states is achieved via exchange of microwave photons.