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

Integrated optical control and enhanced coherence of ion qubits via multi-wavelength photonics

Robert Niffenegger, Jules Stuart, Cheryl M. Sorace-Agaskar, Dave Kharas, Suraj Bramhavar, Colin Bruzewicz, William Loh, Robert McConnell, David Reens, Gavin N. West, Jeremy Sage, John Chiaverini

Published Jan 14, 2020• 4 citations
OpenAlex

Abstract

Monolithic integration of control technologies for atomic systems presents a promising route to the development of quantum computers and portable quantum sensors. Trapped atomic ions form the basis of high-fidelity quantum information processors and high-accuracy optical clocks, but currently rely on free-space optics for ion control, limiting portability and scalability. Here we demonstrate a surface-electrode ion trap which delivers all wavelengths required for ionization, cooling, coherent operations, and quantum-state preparation and detection of Sr$^{+}$ qubits using integrated waveguides and grating couplers. Laser light from the violet to the infrared is coupled onto the chip via an optical-fiber array, creating an inherently stable optical path that we use to demonstrate qubit coherence resilient to platform vibrations. This demonstration of CMOS-compatible integrated-photonic surface-trap fabrication, robust packaging, and enhanced qubit coherence represents a key advance in the development of portable trapped-ion quantum sensors and clocks, and it lights the way toward the complete, individual control of larger numbers of ions in quantum information processing systems.

Related papers

Integrated multi-wavelength control of an ion qubit

Robert Niffenegger, Jules Stuart, Cheryl M. Sorace-Agaskar +10 more

Abstract Monolithic integration of control technologies for atomic systems is a promising route to the development of quantum computers and portable quantum sensors1–4. Trapped atomic ions form the basis of high-fidelity quantum information processors5, 6 and high-accuracy optical clocks7. However, current implementations rely on free-space optics for ion control, which limits their portability and scalability. Here we demonstrate a surface-electrode ion-trap chip8, 9 using integrated waveguides and grating couplers, which delivers all the wavelengths of light required for ionization, cooling, coherent operations and quantum state preparation and detection of Sr+ qubits. Laser light from violet to infrared is coupled onto the chip via an optical-fibre array, creating an inherently stable optical path, which we use to demonstrate qubit coherence that is resilient to platform vibrations. This demonstration of CMOS-compatible integrated photonic surface-trap fabrication, robust packaging and enhanced qubit coherence is a key advance in the development of portable trapped-ion quantum sensors and clocks, providing a way towards the complete, individual control of larger numbers of ions in quantum information processing systems.

•Jan 1, 2020•68 citations

Utilizing integrated photonic technology for trapped-ion quantum computing

May E. Kim

Trapped-ion qubits have been advantageous in quantum information processing due to their long coherence times and high-fidelity state preparation, logic gate operation, and readout. In recent years, we have fabricated chips with electrodes – for generating the electric field for trapping ions – and photonic waveguides and grating out-couplers – for delivering light to the ions. The integrated photonics can potentially lower the laser power requirement and lead to faster gates; however, there are challenges that need to be overcome for the platform to be beneficial. Here, we demonstrate single and two qubit gates with Sr+ trapped ion qubits, driven by delivering light to the ions both via free space and integrated photonics. We show that robust quantum logic is within reach using the integrated photonic platform, and the approaches we are taking in mitigating current challenges.

Quantum Computing, Communication, and Simulation•Mar 13, 2024•0 citations

Integrated optical multi-ion quantum logic

Karan K. Mehta, Chi Zhang, Maciej Malinowski +3 more

Abstract Practical and useful quantum information processing requires substantial improvements with respect to current systems, both in the error rates of basic operations and in scale. The fundamental qualities of individual trapped-ion1 qubits are promising for long-term systems2, but the optics involved in their precise control are a barrier to scaling3. Planar-fabricated optics integrated within ion-trap devices can make such systems simultaneously more robust and parallelizable, as suggested by previous work with single ions4. Here we use scalable optics co-fabricated with a surface-electrode ion trap to achieve high-fidelity multi-ion quantum logic gates, which are often the limiting elements in building up the precise, large-scale entanglement that is essential to quantum computation. Light is efficiently delivered to a trap chip in a cryogenic environment via direct fibre coupling on multiple channels, eliminating the need for beam alignment into vacuum systems and cryostats and lending robustness to vibrations and beam-pointing drifts. This allows us to perform ground-state laser cooling of ion motion and to implement gates generating two-ion entangled states with fidelities greater than 99.3(2) per cent. This work demonstrates hardware that reduces noise and drifts in sensitive quantum logic, and simultaneously offers a route to practical parallelization for high-fidelity quantum processors5. Similar devices may also find applications in atom- and ion-based quantum sensing and timekeeping6.

•Jan 1, 2020•249 citations

Trapped ion qubit and clock operations with a visible wavelength photonic coil resonator stabilized integrated Brillouin laser

Nitesh Chauhan, Caron, Christopher, Jiawei Wang +5 more

Integrating precise, stable, ultra-low noise visible light lasers into atomic systems is critical for advancing quantum information sciences and improving scalability and portability. Trapped ions are a leading approach for high-fidelity quantum computing, high-accuracy optical clocks, and precision quantum sensors. However, current ion-based systems rely on bulky, lab-scale precision lasers and optical stabilization cavities for optical clock and qubit operations, constraining the size, weight, scalability, and portability of atomic systems. Chip-scale integration of ultra-low noise lasers and reference cavities operating directly at optical clock transitions and capable of qubit and clock operations will represent a major transformation in atom and trapped ion-based quantum technologies. However, this goal has remained elusive. Here we report the first demonstration of chip-scale optical clock and qubit operations on a trapped ion using a photonic integrated direct-drive visible wavelength Brillouin laser stabilized to an integrated 3-meter coil-resonator reference cavity and the optical clock transition of a $^{88}$Sr$^+$ ion trapped on a surface electrode chip. We also demonstrate for the first time, to the best of our knowledge, trapped-ion spectroscopy and qubit operations such as Rabi oscillations and high fidelity (99%) qubit state preparation and measurement (SPAM) using direct drive integrated photonic technologies without bulk optic stabilization cavities or second harmonic generation. Our chip-scale stabilized Brillouin laser exhibits a 6 kHz linewidth with the 0.4 Hz quadrupole transition of $^{88}$Sr$^+$ and a self-consistent coherence time of 60 $μ$s via Ramsey interferometry on the trapped ion qubit. Furthermore, we demonstrate the stability of the locked Brillouin laser to 5$\times10^{-13}/ \sqrtτ$ at 1 second using dual optical clocks.

arXiv:2402.16742•Feb 26, 2024•11 citations

Autonomous multi-ion optical clock with on-chip integrated photonic light delivery

Tharon D. Morrison, Joonhyuk Kwon, Matthew A. Delaney +4 more

Integrated photonics in trapped-ion systems are critical for the realization of applications such as portable optical atomic clocks and scalable quantum computers. However, system-level integration of all required functionalities remains a key challenge. In this work, we demonstrate an autonomously operating optical clock having a short-term frequency instability of $3.14(5)\times 10^{-14} / \sqrtτ$ using an ensemble of four $^{171}\textrm{Yb}^{+}$ ions trapped in a multi-site surface-electrode trap at room temperature. All clock operations are performed with light delivered via on-chip waveguides. We showcase the system's resilience through sustained, autonomous operation featuring automated ion shuttling and reloading to mitigate ion loss during interleaved clock measurements. This work paves the way beyond component-level functionality to establish a viable and robust architecture for the next generation of portable, multi-ion quantum sensors and computers.

quant-pharXiv:2512.08921•Dec 10, 2025•0 citations

Trapped Ion Qubit Gates and Entanglement Driven by an Integrated Photonic Laser

Chris Caron, Zhenyu Wei, Andrei Isichenko +8 more

Trapped ions are a leading technology for quantum computing, but their reliance on bespoke tabletop laser and optical systems remains a major obstacle to scaling and robustness. Integrated silicon nitride lasers, compatible with future monolithic integration with surface electrode ion traps, have recently demonstrated frequency-selective qubit state preparation and measurement as well as interrogation of an optical clock transition. However, coherent qubit gates impose even more stringent requirements on laser phase noise, and their implementation with integrated laser sources has remained an outstanding challenge. Here, we use a visible-wavelength integrated Brillouin laser stabilized to an integrated coil resonator to drive coherent single- and two-qubit gates with \Sr optical qubits. We measure an average single-qubit fidelity of $99.61\%\pm 0.03\%$ per Clifford gate with randomized benchmarking and use a two-qubit Mølmer-Sørensen interaction to generate an entangled Bell state with a fidelity of $92.35\% \pm 1.50\%$. The qubit exhibits a bare Ramsey coherence time of $659 \pm 9~μ$s, more than a tenfold improvement over our previous implementation, which extends to $1.750 \pm 0.033$~ms with an echo. These results demonstrate, for the first time, that integrated visible-wavelength narrow-linewidth photonic lasers can meet the phase-noise requirements for coherent quantum logic with trapped ion optical qubits, providing a path for scalable optical systems integrated within trapped ion quantum processors.

quant-pharXiv:2609.07708•Sep 8, 2026•0 citations
Monolithic integration of control technologies for atomic systems presents a promising route to the development of quantum computers and portable quantum sensors. Trapped atomic ions form the basis of high-fidelity quantum information processors and high-accuracy optical clocks, but currently rely on free-space optics for ion control, limiting portability and scalability. Here we demonstrate a surface-electrode ion trap which delivers all wavelengths required for ionization, cooling, coherent operations, and quantum-state preparation and detection of Sr+^{+}+ qubits using integrated waveguides and grating couplers. Laser light from the violet to the infrared is coupled onto the chip via an optical-fiber array, creating an inherently stable optical path that we use to demonstrate qubit coherence resilient to platform vibrations. This demonstration of CMOS-compatible integrated-photonic surface-trap fabrication, robust packaging, and enhanced qubit coherence represents a key advance in the development of portable trapped-ion quantum sensors and clocks, and it lights the way toward the complete, individual control of larger numbers of ions in quantum information processing systems.
Abstract Monolithic integration of control technologies for atomic systems is a promising route to the development of quantum computers and portable quantum sensors1–4. Trapped atomic ions form the basis of high-fidelity quantum information processors5, 6 and high-accuracy optical clocks7. However, current implementations rely on free-space optics for ion control, which limits their portability and scalability. Here we demonstrate a surface-electrode ion-trap chip8, 9 using integrated waveguides and grating couplers, which delivers all the wavelengths of light required for ionization, cooling, coherent operations and quantum state preparation and detection of Sr+ qubits. Laser light from violet to infrared is coupled onto the chip via an optical-fibre array, creating an inherently stable optical path, which we use to demonstrate qubit coherence that is resilient to platform vibrations. This demonstration of CMOS-compatible integrated photonic surface-trap fabrication, robust packaging and enhanced qubit coherence is a key advance in the development of portable trapped-ion quantum sensors and clocks, providing a way towards the complete, individual control of larger numbers of ions in quantum information processing systems.
Trapped-ion qubits have been advantageous in quantum information processing due to their long coherence times and high-fidelity state preparation, logic gate operation, and readout. In recent years, we have fabricated chips with electrodes – for generating the electric field for trapping ions – and photonic waveguides and grating out-couplers – for delivering light to the ions. The integrated photonics can potentially lower the laser power requirement and lead to faster gates; however, there are challenges that need to be overcome for the platform to be beneficial. Here, we demonstrate single and two qubit gates with Sr+ trapped ion qubits, driven by delivering light to the ions both via free space and integrated photonics. We show that robust quantum logic is within reach using the integrated photonic platform, and the approaches we are taking in mitigating current challenges.
Abstract Practical and useful quantum information processing requires substantial improvements with respect to current systems, both in the error rates of basic operations and in scale. The fundamental qualities of individual trapped-ion1 qubits are promising for long-term systems2, but the optics involved in their precise control are a barrier to scaling3. Planar-fabricated optics integrated within ion-trap devices can make such systems simultaneously more robust and parallelizable, as suggested by previous work with single ions4. Here we use scalable optics co-fabricated with a surface-electrode ion trap to achieve high-fidelity multi-ion quantum logic gates, which are often the limiting elements in building up the precise, large-scale entanglement that is essential to quantum computation. Light is efficiently delivered to a trap chip in a cryogenic environment via direct fibre coupling on multiple channels, eliminating the need for beam alignment into vacuum systems and cryostats and lending robustness to vibrations and beam-pointing drifts. This allows us to perform ground-state laser cooling of ion motion and to implement gates generating two-ion entangled states with fidelities greater than 99.3(2) per cent. This work demonstrates hardware that reduces noise and drifts in sensitive quantum logic, and simultaneously offers a route to practical parallelization for high-fidelity quantum processors5. Similar devices may also find applications in atom- and ion-based quantum sensing and timekeeping6.
Integrating precise, stable, ultra-low noise visible light lasers into atomic systems is critical for advancing quantum information sciences and improving scalability and portability. Trapped ions are a leading approach for high-fidelity quantum computing, high-accuracy optical clocks, and precision quantum sensors. However, current ion-based systems rely on bulky, lab-scale precision lasers and optical stabilization cavities for optical clock and qubit operations, constraining the size, weight, scalability, and portability of atomic systems. Chip-scale integration of ultra-low noise lasers and reference cavities operating directly at optical clock transitions and capable of qubit and clock operations will represent a major transformation in atom and trapped ion-based quantum technologies. However, this goal has remained elusive. Here we report the first demonstration of chip-scale optical clock and qubit operations on a trapped ion using a photonic integrated direct-drive visible wavelength Brillouin laser stabilized to an integrated 3-meter coil-resonator reference cavity and the optical clock transition of a 88^{88}88Sr+^++ ion trapped on a surface electrode chip. We also demonstrate for the first time, to the best of our knowledge, trapped-ion spectroscopy and qubit operations such as Rabi oscillations and high fidelity (99%) qubit state preparation and measurement (SPAM) using direct drive integrated photonic technologies without bulk optic stabilization cavities or second harmonic generation. Our chip-scale stabilized Brillouin laser exhibits a 6 kHz linewidth with the 0.4 Hz quadrupole transition of 88^{88}88Sr+^++ and a self-consistent coherence time of 60 μμμs via Ramsey interferometry on the trapped ion qubit. Furthermore, we demonstrate the stability of the locked Brillouin laser to 5×10−13/τ\times10^{-13}/ \sqrtτ×10−13/τ​ at 1 second using dual optical clocks.
Integrated photonics in trapped-ion systems are critical for the realization of applications such as portable optical atomic clocks and scalable quantum computers. However, system-level integration of all required functionalities remains a key challenge. In this work, we demonstrate an autonomously operating optical clock having a short-term frequency instability of 3.14(5)×10−14/τ3.14(5)\times 10^{-14} / \sqrtτ3.14(5)×10−14/τ​ using an ensemble of four 171Yb+^{171}\textrm{Yb}^{+}171Yb+ ions trapped in a multi-site surface-electrode trap at room temperature. All clock operations are performed with light delivered via on-chip waveguides. We showcase the system's resilience through sustained, autonomous operation featuring automated ion shuttling and reloading to mitigate ion loss during interleaved clock measurements. This work paves the way beyond component-level functionality to establish a viable and robust architecture for the next generation of portable, multi-ion quantum sensors and computers.
Trapped ions are a leading technology for quantum computing, but their reliance on bespoke tabletop laser and optical systems remains a major obstacle to scaling and robustness. Integrated silicon nitride lasers, compatible with future monolithic integration with surface electrode ion traps, have recently demonstrated frequency-selective qubit state preparation and measurement as well as interrogation of an optical clock transition. However, coherent qubit gates impose even more stringent requirements on laser phase noise, and their implementation with integrated laser sources has remained an outstanding challenge. Here, we use a visible-wavelength integrated Brillouin laser stabilized to an integrated coil resonator to drive coherent single- and two-qubit gates with \Sr optical qubits. We measure an average single-qubit fidelity of 99.61%±0.03%99.61\%\pm 0.03\%99.61%±0.03% per Clifford gate with randomized benchmarking and use a two-qubit Mølmer-Sørensen interaction to generate an entangled Bell state with a fidelity of 92.35%±1.50%92.35\% \pm 1.50\%92.35%±1.50%. The qubit exhibits a bare Ramsey coherence time of 659±9 μ659 \pm 9~μ659±9 μs, more than a tenfold improvement over our previous implementation, which extends to 1.750±0.0331.750 \pm 0.0331.750±0.033~ms with an echo. These results demonstrate, for the first time, that integrated visible-wavelength narrow-linewidth photonic lasers can meet the phase-noise requirements for coherent quantum logic with trapped ion optical qubits, providing a path for scalable optical systems integrated within trapped ion quantum processors.