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:2206.04488 · Physical Review Letters

Spin-Echo Silencing Using a Current-Biased Frequency-Tunable Resonator

V. Ranjan, Yutian Wen, Ailsa Keyser, Sergey Kubatkin, Andrey V. Danilov, T. Lindström, Patrice Bertet, Sebastian E. de Graaf

Published Oct 28, 2022• 10 citations
arXivHTMLPDF

Abstract

The ability to control microwave emission from a spin ensemble is a requirement of several quantum memory protocols. Here, we demonstrate such ability by using a resonator whose frequency can be rapidly tuned with a bias current. We store excitations in an ensemble of rare-earth ions and suppress on demand the echo emission ("echo silencing") by two methods: (1) detuning the resonator during the spin rephasing, and (2) subjecting spins to magnetic field gradients generated by the bias current itself. We also show that spin coherence is preserved during silencing.

DOI
10.1103/physrevlett.129.180504

Related papers

Stark control of solid-state quantum memory with spin-wave storage

Mohammed K. Alqedra, Sebastian P. Horvath, Adam Kinos +3 more

Quantum memories for quantum communication need to be able to store photons for an extended time and then to release them on demand. This can be achieved in atomic frequency comb ensemble-based quantum memories by control pulses that transfer the excitation to and from long-lived spin states. However, such pulses can give rise to coherent and incoherent noise due to their interaction with the memory ensemble. In this paper, we experimentally demonstrate the ability to switch off the coherent noise from such control pulses during the echo emission in a spin-wave quantum memory, using the linear Stark effect in rare-earth-ion doped crystals. By applying an electric-field pulse, the echo emission was coherently switched off prior to the first spin transfer pulse, and the stored data pulse was restored only when both an optical recall pulse and a rephasing electrical pulse were applied, giving a high degree of control of both desired and undesired emissions. We estimate the effectiveness of this technique by turning off the free-induction decay of a narrow ensemble of ions. This technique can thus improve the noise performance of spin-wave storage at the single-photon level by quenching coherent optical radiation created by strong control pulses. The method demonstrated here represents a proof of principle that the spin-wave storage scheme can be combined with Stark control. The combined scheme serves as an addition to the toolbox of techniques that can be used to realize a full version of a quantum repeater. Published by the American Physical Society 2024

arXiv:2211.17206•Physical Review A•Jan 5, 2024•4 citations

Controlling Photon Echoes with the Light Shift

Hamish Callum McDonald

Recent progress with rare-earth-ion ensemble quantum memories has resulted in a family of echo-memory protocols which use sequences of pulsed light fields to recall a pulse stored in the ensemble earlier. The simplest of these protocols, the two-pulse photon echo, has been deemed too noisy to operate in the single-photon regime.\n\nIn this work we introduce and investigate the LiSPER protocol, which involves using off-resonant pulses to control the recall of the stored pulse from the ensemble. In the LiSPER protocol, two off-resonant pulses dynamically tune the resonant frequencies of the ions in the ensemble such that an unwanted noisy echo is suppressed and a less noisy echo of the input pulse is emitted at a later time. A theoretical basis for LiSPER is formed with analytical calculations and numerical simulations, and the dependence of the protocol efficiency on parameters of the off-resonant pulses is characterised. Also presented are the results of experiments performed using a praseodymium ion ensemble. These results agree qualitatively with the theoretical work, although the entire LiSPER protocol is not demonstrated.

•Jan 1, 2016•1 citation

Spin frequency comb echo memory controlled by a pulsed-gradient of magnetic field

K. I. Gerasimov, S. A. Moiseev, V. I. Morozov +1 more

The controllable storage and on demand retrieval of the microwave pulses by using the photon echo quantum memory approach based on a spin frequency comb of inhomogeneous broadening (SFC- protocol) have been demonstrated. We have used an electron-nuclear spin ensemble of tetracyanoethylene anion radicals in toluene which has a natural periodic structure of narrow electron-spin resonance (ESR) hyperfine lines. On-demand retrieval of the stored field has been realized by using two pulses of the magnetic field gradient of an opposite polarity which hold the electron spins in a dephased excited state during the storage time. The obtained experimental results demonstrate promising properties for coherent controlling the electron-nuclear spin ensemble of radicals in liquid that could be useful for implementation of room-temperature broadband quantum memory.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Mar 25, 2015•2 citations

Proposal for a coherent quantum memory for propagating microwave photons

M Afzelius, Nicolas Sangouard, G Johansson +2 more

We describe a multi-mode quantum memory for propagating microwave photons that combines a solid-state spin ensemble resonantly coupled to a frequency tunable single-mode microwave cavity. We first show that high efficiency mapping of the quantum state transported by a free photon to the spin ensemble is possible both for strong and weak coupling between the cavity mode and the spin ensemble. We also show that even in the weak coupling limit unit efficiency and faithful retrieval can be obtained through time reversal inhomogeneous dephasing based on spin echo techniques. This is possible provided that the cavity containing the spin ensemble and the transmission line are impedance matched. We finally discuss the prospects for an experimental implementation using a rare-earth doped crystal coupled to a superconducting resonator.

arXiv:1301.1858•New Journal of Physics•Jun 17, 2013•55 citations

Proposal for a coherent quantum memory for propagating microwave photons

Afzelius, M., Nicolas Sangouard, Göran Johansson +2 more

We describe a multi-mode quantum memory for propagating microwave photons that combines a solid-state spin ensemble resonantly coupled to a frequency tunable single-mode microwave cavity. We first show that high efficiency mapping of the quantum state transported by a free photon to the spin ensemble is possible both for strong and weak coupling between the cavity mode and the spin ensemble. We also show that even in the weak coupling limit unit efficiency and faithful retrieval can be obtained through time reversal inhomogeneous dephasing based on spin echo techniques. This is possible provided that the cavity containing the spin ensemble and the transmission line are impedance matched. We finally discuss the prospects for an experimental implementation using a rare-earth doped crystal coupled to a superconducting resonator.

•Jan 1, 2013•21 citations

Broadband photonic quantum interface based on a cavity-protected rare-earth ensemble

Tian Zhong, Jonathan M. Kindem, Jake Rochman +1 more

Rare-earth ions doped in crystals are renowned for their excellent coherence properties and large inhomogeneous broadening, which make them ideal for quantum interfaces with broadband photons. These properties have made them one of the leading technologies in quantum optical memories and a promising candidate for optical-to-microwave conversion. To take advantage of the full bandwidth of the rare-earth ensemble, one must overcome the decoherence of a broadband collective excitation due to inhomogeneous broadening. To this end, techniques based on controllable rephasing, such as atomic frequency comb (AFC) or controlled reversible inhomogeneous broadening (CRIB) memories, have been developed with great success. Recently, an alternative method was proposed to suppress the decoherence of an inhomogeneous ensemble via strong coupling to a cavity, a phenomenon called cavity protection. This technique has been demonstrated in the microwave domain with an NV spin ensemble, but has not been demonstrated in the optical domain. Here, we demonstrate cavity protection in the optical domain at the single photon level using an ensemble of rare earths ions coupled to a nanophotonic resonator. The reduction in decoherence due to the cavity-protection effect enables transfer of ultrafast (~50 GHz) frequency qubits into the collective ion excitation and retrieval with 98.7% fidelity. Building on these results to transfer these excitations to long-lived spin states would enable broadband, on-demand quantum memories. Furthermore, this works compliments the work done coupling rare-earths to superconducting resonators in the microwave regime with potential for applications in optical-to-microwave transducers.

•Jun 2, 2017•0 citations
The ability to control microwave emission from a spin ensemble is a requirement of several quantum memory protocols. Here, we demonstrate such ability by using a resonator whose frequency can be rapidly tuned with a bias current. We store excitations in an ensemble of rare-earth ions and suppress on demand the echo emission ("echo silencing") by two methods: (1) detuning the resonator during the spin rephasing, and (2) subjecting spins to magnetic field gradients generated by the bias current itself. We also show that spin coherence is preserved during silencing.
Quantum memories for quantum communication need to be able to store photons for an extended time and then to release them on demand. This can be achieved in atomic frequency comb ensemble-based quantum memories by control pulses that transfer the excitation to and from long-lived spin states. However, such pulses can give rise to coherent and incoherent noise due to their interaction with the memory ensemble. In this paper, we experimentally demonstrate the ability to switch off the coherent noise from such control pulses during the echo emission in a spin-wave quantum memory, using the linear Stark effect in rare-earth-ion doped crystals. By applying an electric-field pulse, the echo emission was coherently switched off prior to the first spin transfer pulse, and the stored data pulse was restored only when both an optical recall pulse and a rephasing electrical pulse were applied, giving a high degree of control of both desired and undesired emissions. We estimate the effectiveness of this technique by turning off the free-induction decay of a narrow ensemble of ions. This technique can thus improve the noise performance of spin-wave storage at the single-photon level by quenching coherent optical radiation created by strong control pulses. The method demonstrated here represents a proof of principle that the spin-wave storage scheme can be combined with Stark control. The combined scheme serves as an addition to the toolbox of techniques that can be used to realize a full version of a quantum repeater. Published by the American Physical Society 2024
Recent progress with rare-earth-ion ensemble quantum memories has resulted in a family of echo-memory protocols which use sequences of pulsed light fields to recall a pulse stored in the ensemble earlier. The simplest of these protocols, the two-pulse photon echo, has been deemed too noisy to operate in the single-photon regime.\n\nIn this work we introduce and investigate the LiSPER protocol, which involves using off-resonant pulses to control the recall of the stored pulse from the ensemble. In the LiSPER protocol, two off-resonant pulses dynamically tune the resonant frequencies of the ions in the ensemble such that an unwanted noisy echo is suppressed and a less noisy echo of the input pulse is emitted at a later time. A theoretical basis for LiSPER is formed with analytical calculations and numerical simulations, and the dependence of the protocol efficiency on parameters of the off-resonant pulses is characterised. Also presented are the results of experiments performed using a praseodymium ion ensemble. These results agree qualitatively with the theoretical work, although the entire LiSPER protocol is not demonstrated.
The controllable storage and on demand retrieval of the microwave pulses by using the photon echo quantum memory approach based on a spin frequency comb of inhomogeneous broadening (SFC- protocol) have been demonstrated. We have used an electron-nuclear spin ensemble of tetracyanoethylene anion radicals in toluene which has a natural periodic structure of narrow electron-spin resonance (ESR) hyperfine lines. On-demand retrieval of the stored field has been realized by using two pulses of the magnetic field gradient of an opposite polarity which hold the electron spins in a dephased excited state during the storage time. The obtained experimental results demonstrate promising properties for coherent controlling the electron-nuclear spin ensemble of radicals in liquid that could be useful for implementation of room-temperature broadband quantum memory.
We describe a multi-mode quantum memory for propagating microwave photons that combines a solid-state spin ensemble resonantly coupled to a frequency tunable single-mode microwave cavity. We first show that high efficiency mapping of the quantum state transported by a free photon to the spin ensemble is possible both for strong and weak coupling between the cavity mode and the spin ensemble. We also show that even in the weak coupling limit unit efficiency and faithful retrieval can be obtained through time reversal inhomogeneous dephasing based on spin echo techniques. This is possible provided that the cavity containing the spin ensemble and the transmission line are impedance matched. We finally discuss the prospects for an experimental implementation using a rare-earth doped crystal coupled to a superconducting resonator.
We describe a multi-mode quantum memory for propagating microwave photons that combines a solid-state spin ensemble resonantly coupled to a frequency tunable single-mode microwave cavity. We first show that high efficiency mapping of the quantum state transported by a free photon to the spin ensemble is possible both for strong and weak coupling between the cavity mode and the spin ensemble. We also show that even in the weak coupling limit unit efficiency and faithful retrieval can be obtained through time reversal inhomogeneous dephasing based on spin echo techniques. This is possible provided that the cavity containing the spin ensemble and the transmission line are impedance matched. We finally discuss the prospects for an experimental implementation using a rare-earth doped crystal coupled to a superconducting resonator.
Rare-earth ions doped in crystals are renowned for their excellent coherence properties and large inhomogeneous broadening, which make them ideal for quantum interfaces with broadband photons. These properties have made them one of the leading technologies in quantum optical memories and a promising candidate for optical-to-microwave conversion. To take advantage of the full bandwidth of the rare-earth ensemble, one must overcome the decoherence of a broadband collective excitation due to inhomogeneous broadening. To this end, techniques based on controllable rephasing, such as atomic frequency comb (AFC) or controlled reversible inhomogeneous broadening (CRIB) memories, have been developed with great success. Recently, an alternative method was proposed to suppress the decoherence of an inhomogeneous ensemble via strong coupling to a cavity, a phenomenon called cavity protection. This technique has been demonstrated in the microwave domain with an NV spin ensemble, but has not been demonstrated in the optical domain. Here, we demonstrate cavity protection in the optical domain at the single photon level using an ensemble of rare earths ions coupled to a nanophotonic resonator. The reduction in decoherence due to the cavity-protection effect enables transfer of ultrafast (~50 GHz) frequency qubits into the collective ion excitation and retrieval with 98.7% fidelity. Building on these results to transfer these excitations to long-lived spin states would enable broadband, on-demand quantum memories. Furthermore, this works compliments the work done coupling rare-earths to superconducting resonators in the microwave regime with potential for applications in optical-to-microwave transducers.