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:0707.3946 · AIP conference proceedings

Implementing Universal Quantum Gates in Coupled Cavities

Dimitris G. Angelakis, Alastair Kay, Theodore E. Simos, George Maroulis

Published Jan 1, 2007• 0 citations
arXivHTMLPDF

Abstract

We propose an array of coupled cavities interacting with two level systems and show how to construct stable, individually addressable, qubits in this system from the long‐lived atom‐photon excitations (polaritons) at each site. We derive the system dynamics and show that is described by an XY Hamiltonian. We proceed by showing how to implement non‐local quantum gates and show that combined with the inherent ability for individual addressing, universal quantum computation is possible in this system. We finally discuss the prospects for experimental implementation using various technologies involving dopants as atoms, NV centers in diamond, quantum dots or Cooper pair boxes.

DOI
10.1063/1.2836195

Related papers

Cluster state quantum computation in coupled cavity arrays

Dimitris G. Angelakis, Alastair Kay

Measurement-based quantum computation has revolutionized quantum information processing, and the physical systems with which it can be implemented. One simply needs the ability to prepare a particular state, known as the cluster state, and subsequently to perform single-qubit measurements on it. Nevertheless, a scalable implementation is yet to be realized. Here we propose a hybrid light-matter system comprised of coupled cavities interacting with two level systems. Utilising the stable, individually addressable, qubits resulting from the localised long-lived atom-photon excitations, we demonstrate how to use the natural system dynamics to `weave' these qubits into a cluster state and propose the implementation of quantum algorithms employing just two rows of qubits. Finally, we briefly discuss the prospects for experimental implementation using atoms, quantum dots or Cooper pair boxes.

arXiv:quant-ph/0702133•Feb 13, 2007•1 citation

Weaving light-matter qubits into a one way quantum computer

Dimitris G. Angelakis, Alastair Kay

The great advantage of measurement-based quantum computation is that one would simply need the ability to prepare a particular state, known as the cluster state, and subsequently to perform single-qubit measurements on it. Nevertheless, a scalable implementation is yet to be realized. Here, we propose a hybrid light–matter system consisting of coupled cavities interacting with two level systems. Utilizing the stable, individually addressable, qubits resulting from the localized long-lived atom–photon excitations, we demonstrate how to use the natural system dynamics to 'weave' these qubits into a cluster state and propose the implementation of quantum algorithms employing just two rows of qubits. Finally, we briefly discuss the prospects for experimental implementation using atoms, quantum dots or Cooper pair boxes.

New Journal of Physics•Feb 12, 2008•23 citations

Quantum computation with coupled quantum dots embedded in optical microcavities

Xin-Qi Li, YiJing Yan

Based on an idea that spatial separation of charge states can enhance quantum coherence, we propose a scheme for a quantum computation with the quantum bit (qubit) constructed from two coupled quantum dots. Quantum information is stored in the electron-hole pair state with the electron and hole located in different dots, which enables the qubit state to be very long-lived. Universal quantum gates involving any pair of qubits are realized by coupling the quantum dots through the cavity photon which is a hopeful candidate for the transfer of long-range information. The operation analysis is carried out by estimating the gate time versus the decoherence time.

arXiv:quant-ph/0203145•Physical review. B, Condensed matter•Apr 23, 2002•31 citations

Quantum computation by optically coupled steady atoms/quantum-dots inside a quantum electro-dynamic cavity

Prabhakar Pradhan, M. P. Anantram, Kang L. Wang

We present a model for quantum computation using n steady 3-level atoms or 3-level quantum dots, kept inside a quantum electro-dynamics (QED) cavity. Our model allows one-qubit operations and the two-qubit controlled-NOT gate as required for universal quantum computation. The n quantum bits are described by two energy levels of each atom/dot. An external laser and n separate pairs of electrodes are used to address a single atom/dot independent of the others, via Stark effect. The third level of each system and an additional common-mode qubit (a cavity photon) are used for realizing the controlled-NOT operation between any pair of qubits. Laser frequency, cavity frequency, and energy levels are far off-resonance, and they are brought to resonance by modifying the energy-levels of a 3-level system using the Stark effect, only at the time of operation.

arXiv:quant-ph/0002006•Feb 2, 2000•6 citations

Photon-blockade-induced Mott transitions and X Y spin models in coupled cavity arrays

Dimitris G. Angelakis, Marcelo França Santos, Sougato Bose

We propose a physical system where photons could exhibit strongly correlated effects. We demonstrate how a Mott-insulator phase of atom-photon excitations (polaritons) can arise in an array of individually addressable coupled electromagnetic cavities when each of these cavities is coupled resonantly to a single two-level system (atom, quantum dot, or Cooper pair). This Mott phase is characterized by the same integral number of net polaritonic excitations with photon blockade providing the required repulsion between the excitations in each site. Detuning the atomic and photonic frequencies suppresses this effect and induces a transition to a photonic superfluid. Finally, on resonance the system can straightforwardly simulate the dynamics of many-body spin systems.

arXiv:quant-ph/0606159•Physical Review A•Sep 28, 2007•565 citations

Cavity polariton blockade for non-local entangling gates with trapped atoms

Vineesha Srivastava, Sven Jandura, Gavin K. Brennen +1 more

Abstract We propose a scheme for realizing multi-qubit entangled W-state and non-local CZ and C 2 Z gates via a cavity polariton blockade mechanism with a system of atomic qubits coupled to a common cavity mode. The polariton blockade is achieved by tuning the system, an N − qubit register, such that no two atoms are simultaneously excited to the qubit excited state, and there is an effective coupling only between the ground state and a singly-excited W state of the qubit register. The control step requires only an external drive of the cavity mode and a global qubit pulse and no individual qubit addressing. We analytically obtain the state preparation error upper bound for an N − qubit W state which scales as ( 1 − 1 / N ) / C where C is the single particle cooperativity. We additionally show the application of the polariton blockade mechanism in realizing a non-local CZ and C 2 Z gate by using a different set of computational qubit states, and characterize the gate infidelity upper bounds which scale as ∼ 1 / C .

arXiv:2502.14781•Quantum Science and Technology•Aug 20, 2025•2 citations
We propose an array of coupled cavities interacting with two level systems and show how to construct stable, individually addressable, qubits in this system from the long‐lived atom‐photon excitations (polaritons) at each site. We derive the system dynamics and show that is described by an XY Hamiltonian. We proceed by showing how to implement non‐local quantum gates and show that combined with the inherent ability for individual addressing, universal quantum computation is possible in this system. We finally discuss the prospects for experimental implementation using various technologies involving dopants as atoms, NV centers in diamond, quantum dots or Cooper pair boxes.
Measurement-based quantum computation has revolutionized quantum information processing, and the physical systems with which it can be implemented. One simply needs the ability to prepare a particular state, known as the cluster state, and subsequently to perform single-qubit measurements on it. Nevertheless, a scalable implementation is yet to be realized. Here we propose a hybrid light-matter system comprised of coupled cavities interacting with two level systems. Utilising the stable, individually addressable, qubits resulting from the localised long-lived atom-photon excitations, we demonstrate how to use the natural system dynamics to `weave' these qubits into a cluster state and propose the implementation of quantum algorithms employing just two rows of qubits. Finally, we briefly discuss the prospects for experimental implementation using atoms, quantum dots or Cooper pair boxes.
The great advantage of measurement-based quantum computation is that one would simply need the ability to prepare a particular state, known as the cluster state, and subsequently to perform single-qubit measurements on it. Nevertheless, a scalable implementation is yet to be realized. Here, we propose a hybrid light–matter system consisting of coupled cavities interacting with two level systems. Utilizing the stable, individually addressable, qubits resulting from the localized long-lived atom–photon excitations, we demonstrate how to use the natural system dynamics to 'weave' these qubits into a cluster state and propose the implementation of quantum algorithms employing just two rows of qubits. Finally, we briefly discuss the prospects for experimental implementation using atoms, quantum dots or Cooper pair boxes.
Based on an idea that spatial separation of charge states can enhance quantum coherence, we propose a scheme for a quantum computation with the quantum bit (qubit) constructed from two coupled quantum dots. Quantum information is stored in the electron-hole pair state with the electron and hole located in different dots, which enables the qubit state to be very long-lived. Universal quantum gates involving any pair of qubits are realized by coupling the quantum dots through the cavity photon which is a hopeful candidate for the transfer of long-range information. The operation analysis is carried out by estimating the gate time versus the decoherence time.
We present a model for quantum computation using n steady 3-level atoms or 3-level quantum dots, kept inside a quantum electro-dynamics (QED) cavity. Our model allows one-qubit operations and the two-qubit controlled-NOT gate as required for universal quantum computation. The n quantum bits are described by two energy levels of each atom/dot. An external laser and n separate pairs of electrodes are used to address a single atom/dot independent of the others, via Stark effect. The third level of each system and an additional common-mode qubit (a cavity photon) are used for realizing the controlled-NOT operation between any pair of qubits. Laser frequency, cavity frequency, and energy levels are far off-resonance, and they are brought to resonance by modifying the energy-levels of a 3-level system using the Stark effect, only at the time of operation.
We propose a physical system where photons could exhibit strongly correlated effects. We demonstrate how a Mott-insulator phase of atom-photon excitations (polaritons) can arise in an array of individually addressable coupled electromagnetic cavities when each of these cavities is coupled resonantly to a single two-level system (atom, quantum dot, or Cooper pair). This Mott phase is characterized by the same integral number of net polaritonic excitations with photon blockade providing the required repulsion between the excitations in each site. Detuning the atomic and photonic frequencies suppresses this effect and induces a transition to a photonic superfluid. Finally, on resonance the system can straightforwardly simulate the dynamics of many-body spin systems.
Abstract We propose a scheme for realizing multi-qubit entangled W-state and non-local CZ and C 2 Z gates via a cavity polariton blockade mechanism with a system of atomic qubits coupled to a common cavity mode. The polariton blockade is achieved by tuning the system, an N − qubit register, such that no two atoms are simultaneously excited to the qubit excited state, and there is an effective coupling only between the ground state and a singly-excited W state of the qubit register. The control step requires only an external drive of the cavity mode and a global qubit pulse and no individual qubit addressing. We analytically obtain the state preparation error upper bound for an N − qubit W state which scales as ( 1 − 1 / N ) / C where C is the single particle cooperativity. We additionally show the application of the polariton blockade mechanism in realizing a non-local CZ and C 2 Z gate by using a different set of computational qubit states, and characterize the gate infidelity upper bounds which scale as ∼ 1 / C .