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:1712.05854 · Physical Review Letters

Deterministic Remote Entanglement of Superconducting Circuits through Microwave Two-Photon Transitions

Philippe Campagne-Ibarcq, E. Zalys-Geller, A. Narla, Shyam Shankar, Philip Reinhold, Luke Burkhart, Christopher J. Axline, Wolfgang Pfaff, Luigi Frunzio, Robert J. Schoelkopf, Michel Devoret

Published May 16, 2018• 181 citations
arXivHTMLPDF

Abstract

Large-scale quantum information processing networks will most probably require the entanglement of distant systems that do not interact directly. This can be done by performing entangling gates between standing information carriers, used as memories or local computational resources, and flying ones, acting as quantum buses. We report the deterministic entanglement of two remote transmon qubits by Raman stimulated emission and absorption of a traveling photon wave packet. We achieve a Bell state fidelity of 73%, well explained by losses in the transmission line and decoherence of each qubit.

DOI
10.1103/physrevlett.120.200501

Related papers

Remote entanglement of transmon qubits

Michael Hatridge, Katrina Sliwa, A. Narla +6 more

An open challenge in quantum information processing with superconducting circuits is to entangle arbitrary pairs of qubits, not simply nearest neighbors. This can be accomplished by first entangling the qubits with flying microwave oscillators in the form of traveling pulses and then performing joint manipulation and measurement on a pair of such flying oscillators at a distant site. This method has the advantage of avoiding the overhead required to move information over large distances via only nearest neighbor coupling while also possessing an extremely high on/off ratio of coupling. Remarkably, such a process is naturally embedded in the act of phase-preserving amplification, which transforms two input modes, termed signal and idler, into a two-mode squeezed output state. For an ideal system, this operation generates heralded, perfectly entangled states between remote qubits with a fifty percent success rate. For an inefficient system, the partial loss of information from the flying states degrades the purity of the entanglement. Data will be shown on such a protocol involving two transmon qubits embedded in superconducting cavities connected to the signal and idler inputs of a Josephson Parametric Converter (JPC) operated as a nearly-quantum limited phase-preserving amplifier. I will also discuss new devices which will allow us to improve the process and achieve high success rates with imperfect hardware. Light refreshments will be served.

Bulletin of the American Physical Society•Mar 3, 2014•0 citations

Deterministic quantum teleportation between distant superconducting chips

Jiawei Qiu, Yang Liu, Niu, Jingjing +10 more

Quantum teleportation~\cite{Bennett1993} is of both fundamental interest and great practical importance in quantum information science. To date, quantum teleportation has been implemented in various physical systems~\cite{Pirandola2015}, among which superconducting qubits are of particular practical significance as they emerge as a leading system to realize large-scale quantum computation~\cite{Arute2019,Wu2021}. Nevertheless, the number of superconducting qubits on the same chip is severely limited by the available chip size, the cooling power, and the wiring complexity. Realization of quantum teleportation and remote computation over qubits on distant superconducting chips is a key quantum communication technology to scaling up the system through a distributed quantum computational network~\cite{Gottesman1999,Eisert2000,Jiang2007,Kimble2008,Monroe2014}. However, this goal has not been realized yet in experiments due to the technical challenge of making a quantum interconnect between distant superconducting chips and the inefficient transfer of flying microwave photons over the lossy interconnects~\cite{Kurpiers2018,Axline2018,Campagne2018,Magnard2020}. Here we demonstrate deterministic teleportation of quantum states and entangling gates between distant superconducting chips connected by a 64-meter-long cable bus featuring an ultralow loss of 0.32~dB/km at cryogenic temperatures, where high fidelity remote entanglement is generated via flying microwave photons utilizing time-reversal-symmetry~\cite{Cirac1997,Korotkov2011}. Apart from the fundamental interest of teleporting macroscopic superconducting qubits over a long distance, our work lays a foundation to realization of large-scale superconducting quantum computation through a distributed computational network~\cite{Gottesman1999,Eisert2000,Jiang2007,Kimble2008,Monroe2014}.

arXiv:2302.08756•Feb 17, 2023•3 citations

Quantum network for information processing on superconducting qubits with dark microwave photons

Ming Hua, Ming‐Jie Tao, Fu‐Guo Deng

We present two one-step schemes to generate the Bell state and construct the controlled-phase gate deterministically on remote transmon qutrits trapped in different resonators connected by a superconducting transmission line for a quantum network. They are implemented with coherent evolutions of the entire system in the all-resonance regime assisted by the dark microwave photons which are robust against the transmission line loss. Different from previous works in other quantum systems for a quantum network, the present proposals do not require classical pulses and ancillary qubits. Our simulations with feasible parameters show that the fidelities of both these schemes exceed 99% which is beyond the fault-tolerant threshold for quantum communication.

•Oct 31, 2015•0 citations

Deterministic Quantum Communication Between Fixed-Frequency Superconducting Qubits via Broadband Resonators

Takeaki Miyamura, Zhiling Wang, Kohei Matsuura +5 more

Quantum communication between remote chips is essential for realizing large-scale superconducting quantum computers. For such communication, itinerant microwave photons propagating through transmission lines offer a promising approach. However, demonstrations to date have relied on frequency-tunable circuit elements to compensate for fabrication-related parameter variations between sender and receiver devices, introducing control complexity and limiting scalability. In this work, we demonstrate deterministic quantum state transfer and remote entanglement generation between fixed-frequency superconducting qubits on separate chips. To compensate for the sender-receiver mismatch, we employ a frequency-tunable photon-generation technique which enables us to adjust the photon frequency without modifying circuit parameters. To enhance the frequency tunability, we implement broadband transfer resonators composed of two coupled coplanar-waveguide resonators, achieving a bandwidth of more than 100 MHz. This broadband design enables successful quantum communication across a 30-MHz range of photon frequencies between the remote qubits. Quantum process tomography reveals state transfer fidelities of around 79% and Bell-state fidelities of around 73% across the full frequency range. Our approach avoids the complexity of the control lines and noise channels, providing a flexible pathway toward scalable quantum networks.

quant-pharXiv:2512.08328•Physical Review Applied•Dec 10, 2025•1 citation

Realization of a Universal Quantum Gate Set for Itinerant Microwave Photons

Kevin Reuer, Jean-Claude Besse, Lucien Wernli +5 more

Deterministic photon-photon gates enable the controlled generation of entanglement between mobile carriers of quantum information.Such gates have thus far been exclusively realized in the optical domain and by relying on postselection.Here, we present a nonpostselected, deterministic, photon-photon gate in the microwave frequency range realized using superconducting circuits.We emit photonic qubits from a source chip and route those qubits to a gate chip with which we realize a universal gate set by combining controlled absorption and reemission with single-qubit gates and qubit-photon controlled-phase gates.We measure quantum process fidelities of 75% for single-and of 57% for two-qubit gates, limited mainly by radiation loss and decoherence.This universal gate set has a wide range of potential applications in superconducting quantum networks.

arXiv:2106.03481•Physical Review X•Jan 12, 2022•34 citations

Theory of Deterministic Entanglement Generation between Remote Superconducting Atoms

Kazuki Koshino, K. Inomata, Zhirong Lin +3 more

Hybrid quantum networks of stationary and ``flying'' qubits are essential for distributed quantum information processing. In superconducting quantum computation, two-qubit gates are currently realized by the interaction between neighboring qubits. The authors propose a gate comprising a superconducting ``atom'' and a microwave photon, in which gate operation is completed $d\phantom{\rule{0}{0ex}}e\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}e\phantom{\rule{0}{0ex}}r\phantom{\rule{0}{0ex}}m\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}s\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}c\phantom{\rule{0}{0ex}}a\phantom{\rule{0}{0ex}}l\phantom{\rule{0}{0ex}}l\phantom{\rule{0}{0ex}}y$ (not probabilistically) upon reflection of the photon. This gate's type can be continuously varied $i\phantom{\rule{0}{0ex}}n$ $s\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}u$, enabling $r\phantom{\rule{0}{0ex}}e\phantom{\rule{0}{0ex}}m\phantom{\rule{0}{0ex}}o\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}e$ entanglement of many ``atoms'' via a single photon, or creation of a quantum domino effect.

Physical Review Applied•Jun 5, 2017•18 citations
Large-scale quantum information processing networks will most probably require the entanglement of distant systems that do not interact directly. This can be done by performing entangling gates between standing information carriers, used as memories or local computational resources, and flying ones, acting as quantum buses. We report the deterministic entanglement of two remote transmon qubits by Raman stimulated emission and absorption of a traveling photon wave packet. We achieve a Bell state fidelity of 73%, well explained by losses in the transmission line and decoherence of each qubit.
An open challenge in quantum information processing with superconducting circuits is to entangle arbitrary pairs of qubits, not simply nearest neighbors. This can be accomplished by first entangling the qubits with flying microwave oscillators in the form of traveling pulses and then performing joint manipulation and measurement on a pair of such flying oscillators at a distant site. This method has the advantage of avoiding the overhead required to move information over large distances via only nearest neighbor coupling while also possessing an extremely high on/off ratio of coupling. Remarkably, such a process is naturally embedded in the act of phase-preserving amplification, which transforms two input modes, termed signal and idler, into a two-mode squeezed output state. For an ideal system, this operation generates heralded, perfectly entangled states between remote qubits with a fifty percent success rate. For an inefficient system, the partial loss of information from the flying states degrades the purity of the entanglement. Data will be shown on such a protocol involving two transmon qubits embedded in superconducting cavities connected to the signal and idler inputs of a Josephson Parametric Converter (JPC) operated as a nearly-quantum limited phase-preserving amplifier. I will also discuss new devices which will allow us to improve the process and achieve high success rates with imperfect hardware. Light refreshments will be served.
Quantum teleportation~\cite{Bennett1993} is of both fundamental interest and great practical importance in quantum information science. To date, quantum teleportation has been implemented in various physical systems~\cite{Pirandola2015}, among which superconducting qubits are of particular practical significance as they emerge as a leading system to realize large-scale quantum computation~\cite{Arute2019,Wu2021}. Nevertheless, the number of superconducting qubits on the same chip is severely limited by the available chip size, the cooling power, and the wiring complexity. Realization of quantum teleportation and remote computation over qubits on distant superconducting chips is a key quantum communication technology to scaling up the system through a distributed quantum computational network~\cite{Gottesman1999,Eisert2000,Jiang2007,Kimble2008,Monroe2014}. However, this goal has not been realized yet in experiments due to the technical challenge of making a quantum interconnect between distant superconducting chips and the inefficient transfer of flying microwave photons over the lossy interconnects~\cite{Kurpiers2018,Axline2018,Campagne2018,Magnard2020}. Here we demonstrate deterministic teleportation of quantum states and entangling gates between distant superconducting chips connected by a 64-meter-long cable bus featuring an ultralow loss of 0.32~dB/km at cryogenic temperatures, where high fidelity remote entanglement is generated via flying microwave photons utilizing time-reversal-symmetry~\cite{Cirac1997,Korotkov2011}. Apart from the fundamental interest of teleporting macroscopic superconducting qubits over a long distance, our work lays a foundation to realization of large-scale superconducting quantum computation through a distributed computational network~\cite{Gottesman1999,Eisert2000,Jiang2007,Kimble2008,Monroe2014}.
We present two one-step schemes to generate the Bell state and construct the controlled-phase gate deterministically on remote transmon qutrits trapped in different resonators connected by a superconducting transmission line for a quantum network. They are implemented with coherent evolutions of the entire system in the all-resonance regime assisted by the dark microwave photons which are robust against the transmission line loss. Different from previous works in other quantum systems for a quantum network, the present proposals do not require classical pulses and ancillary qubits. Our simulations with feasible parameters show that the fidelities of both these schemes exceed 99% which is beyond the fault-tolerant threshold for quantum communication.
Quantum communication between remote chips is essential for realizing large-scale superconducting quantum computers. For such communication, itinerant microwave photons propagating through transmission lines offer a promising approach. However, demonstrations to date have relied on frequency-tunable circuit elements to compensate for fabrication-related parameter variations between sender and receiver devices, introducing control complexity and limiting scalability. In this work, we demonstrate deterministic quantum state transfer and remote entanglement generation between fixed-frequency superconducting qubits on separate chips. To compensate for the sender-receiver mismatch, we employ a frequency-tunable photon-generation technique which enables us to adjust the photon frequency without modifying circuit parameters. To enhance the frequency tunability, we implement broadband transfer resonators composed of two coupled coplanar-waveguide resonators, achieving a bandwidth of more than 100 MHz. This broadband design enables successful quantum communication across a 30-MHz range of photon frequencies between the remote qubits. Quantum process tomography reveals state transfer fidelities of around 79% and Bell-state fidelities of around 73% across the full frequency range. Our approach avoids the complexity of the control lines and noise channels, providing a flexible pathway toward scalable quantum networks.
Deterministic photon-photon gates enable the controlled generation of entanglement between mobile carriers of quantum information.Such gates have thus far been exclusively realized in the optical domain and by relying on postselection.Here, we present a nonpostselected, deterministic, photon-photon gate in the microwave frequency range realized using superconducting circuits.We emit photonic qubits from a source chip and route those qubits to a gate chip with which we realize a universal gate set by combining controlled absorption and reemission with single-qubit gates and qubit-photon controlled-phase gates.We measure quantum process fidelities of 75% for single-and of 57% for two-qubit gates, limited mainly by radiation loss and decoherence.This universal gate set has a wide range of potential applications in superconducting quantum networks.
Hybrid quantum networks of stationary and ``flying'' qubits are essential for distributed quantum information processing. In superconducting quantum computation, two-qubit gates are currently realized by the interaction between neighboring qubits. The authors propose a gate comprising a superconducting ``atom'' and a microwave photon, in which gate operation is completed $d\phantom{\rule{0}{0ex}}e\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}e\phantom{\rule{0}{0ex}}r\phantom{\rule{0}{0ex}}m\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}s\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}c\phantom{\rule{0}{0ex}}a\phantom{\rule{0}{0ex}}l\phantom{\rule{0}{0ex}}l\phantom{\rule{0}{0ex}}y$ (not probabilistically) upon reflection of the photon. This gate's type can be continuously varied $i\phantom{\rule{0}{0ex}}n$ $s\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}u$, enabling $r\phantom{\rule{0}{0ex}}e\phantom{\rule{0}{0ex}}m\phantom{\rule{0}{0ex}}o\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}e$ entanglement of many ``atoms'' via a single photon, or creation of a quantum domino effect.