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:1409.4852 · Physical Review B

Fast long-distance control of spin qubits by photon-assisted cotunneling

Peter Stano, Jelena Klinovaja, Floris Braakman, Lieven M. K. Vandersypen, Daniel Loss

Published Aug 4, 2015• 21 citations
arXivHTMLPDF

Abstract

We investigate theoretically the long-distance coupling and spin exchange in an array of quantum dot spin qubits in the presence of microwaves. We find that photon-assisted cotunneling is boosted at resonances between photon and energies of virtually occupied excited states and show how to make it spin selective. We identify configurations that enable fast switching and spin echo sequences for efficient and nonlocal manipulation of spin qubits. We devise configurations in which the near-resonantly boosted cotunneling provides nonlocal coupling which, up to certain limit, does not diminish with distance between the manipulated dots before it decays weakly with inverse distance.

DOI
10.1103/physrevb.92.075302

Related papers

Coherent Spin-Spin Coupling Mediated by Virtual Microwave Photons

Patrick Harvey-Collard, Jurgen Dijkema, Guoji Zheng +3 more

We report the coherent coupling of two electron spins at a distance via virtual microwave photons.Each spin is trapped in a silicon double quantum dot at either end of a superconducting resonator, achieving spinphoton couplings up to around g s =2π ¼ 40 MHz.As the two spins are brought into resonance with each other, but detuned from the photons, an avoided crossing larger than the spin linewidths is observed with an exchange splitting around 2J=2π ¼ 20 MHz.In addition, photon-number states are resolved from the shift 2χ s =2π ¼ -13 MHz that they induce on the spin frequency.These observations demonstrate that we reach the strong dispersive regime of circuit quantum electrodynamics with spins.Achieving spin-spin coupling without real photons is essential to long-range two-qubit gates between spin qubits and scalable networks of spin qubits on a chip.

arXiv:2108.01206•Physical Review X•May 2, 2022•104 citations

Circuit quantum electrodynamics with two remote electron spins

Patrick Harvey-Collard, Jurgen Dijkema, Guoji Zheng +3 more

We report the coherent coupling of two electron spins at a distance via virtual microwave photons. Each spin is trapped in a silicon double quantum dot at either end of a superconducting resonator, achieving spin-photon couplings up to around $g_s/2\pi = 40 \text{MHz}$. As the two spins are brought into resonance with each other, but detuned from the photons, an avoided crossing larger than the spin linewidths is observed with an exchange splitting around $2J/2\pi = 20 \text{MHz}$. In addition, photon number states are resolved from the shift $2\chi_s/2\pi = -13 \text{MHz}$ they induce on the spin frequency. These results could enable long-range two-qubit gates between spin qubits and scalable networks of spin qubits on a chip.

•Aug 2, 2021•1 citation

Long-distance entangling gates between quantum dot spins mediated by a superconducting resonator

Ada Warren, Edwin Barnes, Sophia E. Economou

Recent experiments with silicon qubits demonstrated strong coupling of a microwave resonator to the spin of a single electron in a double quantum dot, opening up the possibility of long-range spin-spin interactions. We present our theoretical calculation of effective interactions between distant quantum dot spins coupled by a resonator, and propose a protocol for fast, high-fidelity two-qubit gates consistent with experimentally demonstrated capabilities. Our simulations show that, in the presence of noise, spin-spin entangling gates significantly outperform cavity-mediated gates on charge qubits.

arXiv:1902.05704•Physical review. B./Physical review. B•Oct 16, 2019•33 citations

Fully Tunable Longitudinal Spin-Photon Interactions in Si and Ge Quantum Dots

Stefano Bosco, Pasquale Scarlino, Jelena Klinovaja +1 more

Spin qubits in silicon and germanium quantum dots are promising platforms for quantum computing, but entangling spin qubits over micrometer distances remains a critical challenge. Current prototypical architectures maximize transversal interactions between qubits and microwave resonators, where the spin state is flipped by nearly resonant photons. However, these interactions cause backaction on the qubit that yields unavoidable residual qubit-qubit couplings and significantly affects the gate fidelity. Strikingly, residual couplings vanish when spin-photon interactions are longitudinal and photons couple to the phase of the qubit. We show that large and tunable spin-photon interactions emerge naturally in state-of-the-art hole spin qubits and that they change from transversal to longitudinal depending on the magnetic field direction. We propose ways to electrically control and measure these interactions, as well as realistic protocols to implement fast high-fidelity two-qubit entangling gates. These protocols work also at high temperatures, paving the way toward the implementation of large-scale quantum processors.

arXiv:2203.17163•Physical Review Letters•Aug 2, 2022•55 citations

Ultra-long-distance interaction between spin qubits

Guido Burkard, Ataç İmamoğlu

We describe a method for implementing deterministic quantum gates between two spin qubits separated by centimeters. Qubits defined by the singlet and triplet states of two exchange coupled quantum dots have recently been shown to possess long coherence times. When the effective nuclear fields in the two asymmetric quantum dots are different, total spin will no longer be a good quantum number and there will be a large electric dipole coupling between the two qubit states. We show that when such a double-quantum-dot qubit is embedded in a superconducting microstrip cavity, the strong coupling regime of cavity quantum electrodynamics lies within reach. Virtual photons in a common cavity mode could mediate coherent interactions between two distant qubits embedded in the same structure; the range of this two-qubit interaction is determined by the wavelength of the microwave transition.

arXiv:cond-mat/0603119•Physical Review B•Jul 24, 2006•151 citations

Virtual-photon-mediated spin-qubit-transmon coupling

Andreas Landig, Jonne Koski, Pasquale Scarlino +10 more

Abstract Spin qubits and superconducting qubits are among the promising candidates for realizing a solid state quantum computer. For the implementation of a hybrid architecture which can profit from the advantages of either approach, a coherent link is necessary that integrates and controllably couples both qubit types on the same chip over a distance that is several orders of magnitude longer than the physical size of the spin qubit. We realize such a link with a frequency-tunable high impedance SQUID array resonator. The spin qubit is a resonant exchange qubit hosted in a GaAs triple quantum dot. It can be operated at zero magnetic field, allowing it to coexist with superconducting qubits on the same chip. We spectroscopically observe coherent interaction between the resonant exchange qubit and a transmon qubit in both resonant and dispersive regimes, where the interaction is mediated either by real or virtual resonator photons.

•Jan 1, 2019•47 citations
We investigate theoretically the long-distance coupling and spin exchange in an array of quantum dot spin qubits in the presence of microwaves. We find that photon-assisted cotunneling is boosted at resonances between photon and energies of virtually occupied excited states and show how to make it spin selective. We identify configurations that enable fast switching and spin echo sequences for efficient and nonlocal manipulation of spin qubits. We devise configurations in which the near-resonantly boosted cotunneling provides nonlocal coupling which, up to certain limit, does not diminish with distance between the manipulated dots before it decays weakly with inverse distance.
We report the coherent coupling of two electron spins at a distance via virtual microwave photons.Each spin is trapped in a silicon double quantum dot at either end of a superconducting resonator, achieving spinphoton couplings up to around g s =2π ¼ 40 MHz.As the two spins are brought into resonance with each other, but detuned from the photons, an avoided crossing larger than the spin linewidths is observed with an exchange splitting around 2J=2π ¼ 20 MHz.In addition, photon-number states are resolved from the shift 2χ s =2π ¼ -13 MHz that they induce on the spin frequency.These observations demonstrate that we reach the strong dispersive regime of circuit quantum electrodynamics with spins.Achieving spin-spin coupling without real photons is essential to long-range two-qubit gates between spin qubits and scalable networks of spin qubits on a chip.
We report the coherent coupling of two electron spins at a distance via virtual microwave photons. Each spin is trapped in a silicon double quantum dot at either end of a superconducting resonator, achieving spin-photon couplings up to around gs/2π=40MHzg_s/2\pi = 40 \text{MHz}gs​/2π=40MHz. As the two spins are brought into resonance with each other, but detuned from the photons, an avoided crossing larger than the spin linewidths is observed with an exchange splitting around 2J/2π=20MHz2J/2\pi = 20 \text{MHz}2J/2π=20MHz. In addition, photon number states are resolved from the shift 2χs/2π=−13MHz2\chi_s/2\pi = -13 \text{MHz}2χs​/2π=−13MHz they induce on the spin frequency. These results could enable long-range two-qubit gates between spin qubits and scalable networks of spin qubits on a chip.
Recent experiments with silicon qubits demonstrated strong coupling of a microwave resonator to the spin of a single electron in a double quantum dot, opening up the possibility of long-range spin-spin interactions. We present our theoretical calculation of effective interactions between distant quantum dot spins coupled by a resonator, and propose a protocol for fast, high-fidelity two-qubit gates consistent with experimentally demonstrated capabilities. Our simulations show that, in the presence of noise, spin-spin entangling gates significantly outperform cavity-mediated gates on charge qubits.
Spin qubits in silicon and germanium quantum dots are promising platforms for quantum computing, but entangling spin qubits over micrometer distances remains a critical challenge. Current prototypical architectures maximize transversal interactions between qubits and microwave resonators, where the spin state is flipped by nearly resonant photons. However, these interactions cause backaction on the qubit that yields unavoidable residual qubit-qubit couplings and significantly affects the gate fidelity. Strikingly, residual couplings vanish when spin-photon interactions are longitudinal and photons couple to the phase of the qubit. We show that large and tunable spin-photon interactions emerge naturally in state-of-the-art hole spin qubits and that they change from transversal to longitudinal depending on the magnetic field direction. We propose ways to electrically control and measure these interactions, as well as realistic protocols to implement fast high-fidelity two-qubit entangling gates. These protocols work also at high temperatures, paving the way toward the implementation of large-scale quantum processors.
We describe a method for implementing deterministic quantum gates between two spin qubits separated by centimeters. Qubits defined by the singlet and triplet states of two exchange coupled quantum dots have recently been shown to possess long coherence times. When the effective nuclear fields in the two asymmetric quantum dots are different, total spin will no longer be a good quantum number and there will be a large electric dipole coupling between the two qubit states. We show that when such a double-quantum-dot qubit is embedded in a superconducting microstrip cavity, the strong coupling regime of cavity quantum electrodynamics lies within reach. Virtual photons in a common cavity mode could mediate coherent interactions between two distant qubits embedded in the same structure; the range of this two-qubit interaction is determined by the wavelength of the microwave transition.
Abstract Spin qubits and superconducting qubits are among the promising candidates for realizing a solid state quantum computer. For the implementation of a hybrid architecture which can profit from the advantages of either approach, a coherent link is necessary that integrates and controllably couples both qubit types on the same chip over a distance that is several orders of magnitude longer than the physical size of the spin qubit. We realize such a link with a frequency-tunable high impedance SQUID array resonator. The spin qubit is a resonant exchange qubit hosted in a GaAs triple quantum dot. It can be operated at zero magnetic field, allowing it to coexist with superconducting qubits on the same chip. We spectroscopically observe coherent interaction between the resonant exchange qubit and a transmon qubit in both resonant and dispersive regimes, where the interaction is mediated either by real or virtual resonator photons.