QUBIT SYSTEMS LABORATORY

Qubit Systems Laboratory (QSL) is a world leader in semiconductor spin qubits. Our broad expertise spans semiconductor growth, device design and modeling, cryogenic control, high-density interconnects and packaging, quantum architecture, and multiqubit demonstrations. Our system architecture is built entirely around scalable semiconductor manufacturing to make quantum computing affordable for practical business and scientific applications.

Our Expertise

HRL is a world leader in developing solid-state technology for quantum computing and networking. Our cutting-edge research spans:

  • Silicon quantum-dot qubits
  • Microwave-dot hybrid systems
  • Quantum benchmarking
  • Quantum system architecture

Building on decades of experience and robust academic collaborations, we're driving quantum innovation forward.

State-of-the-Art Facilities

Our Malibu campus boasts:

  • On-site epitaxial semiconductor growth tools
  • 10,000-square foot nano-fabrication cleanroom
  • High-performance computational resources
  • Cryogenic test and measurement laboratories

Fun fact: This is the same site where the self-aligned MOSFET and the world's first laser were invented!

With HRL's recent acquisition by IBM, we are aggressively transitioning much of our quantum dot fabrication to Anderon.

The HRL Advantage

  1. Long-term vision: We're committed to realizing the full potential of quantum technology beyond immediate applications.
  2. Collaborative approach: Our diverse team brings together a wide range of skills and backgrounds.
  3. Vertical integration: On-site capabilities enable rapid development cycles from growth to testing.
  4. Pioneering spirit: We pursue novel technological approaches with demonstrated advantages.
  5. Proven track record: HRL's leadership in key enabling technologies spans decades.

Join Our Team

We're always looking for passionate scientists, engineers, software developers and students to help shape the quantum future.

Explore our open positions and be part of something extraordinary.

Selected HRL Publications

Commercially relevant quantum computers will require large numbers of high-performing qubits that can be manufactured, integrated and controlled at scale.
"A digitally controlled silicon quantum processing unit," Members of the HRL Quantum Team and Collaborators, Nature 655, 1154-1159 (2026)
The promise of quantum computation is contingent upon physical qubits with both low gate error rate and broad scalability.
"Two-dimensional Si spin qubit arrays with multilevel interconnects," Sieu Ha et al., PRX Quantum 6, 030327 (2025). (arXiv)
We demonstrate coherent control of a three-electron exchange-only spin qubit with the quantum dots arranged in a close-packed triangular geometry.
"Coherent control of a triangular exchange-only spin qubit," Edwin Acuna et al., Phys. Rev. Applied 22, 044057 (2024) arXiv (2024) .
We demonstrate a full-permutation dynamical decoupling technique that cyclically exchanges the spins in a triple-quantum-dot qubit.
"Full-Permutation Dynamical Decoupling in Triple-Quantum-Dot Spin Qubits," Bo Sun et al., PRX Quantum, 5, 020356 (2024) .
We demonstrate universal logic operations with two EO qubits in silicon, including single-qubit gates, CNOT, CZ, and SWAP. We also demonstrate LCCZ, which is expected to reduce leakage spreading in future quantum processors.
"Universal logic with encoded spin qubits in silicon," A. J. Weinstein, Nature 615, 817 (2023). (arXiv) (Informational YouTube Video)
We demonstrate rapid, high-fidelity state preparation and measurement in exchange-only Si/SiGe triple-quantum-dot qubits.
"Fast and high-fidelity state preparation and measurement in triple-quantum-dot spin qubits," J. Z. Blumoff et al., Quantum 3, 010352 (2022). (arXiv)
We present an exchange-only Si qubit device platform that combines the throughput of CMOS-like wafer processing with the versatility of direct-write lithography.
"A flexible design platform for Si/SiGe exchange-only qubits with low disorder," Wonill Ha et al., Nano Lett.2022, 22, 3, 1443 (2021). (arXiv)
We design and train a convolutional neural network to quantify qualitative features affecting device functionality.
"Optimization of quantum-dot qubit fabrication via machine learning," Antonio B. Mei et al., Appl. Phys. Lett., 118, 204001 (2021). (arXiv)
DAPS allows us to systematically probe multiple valley and orbital states of individual dots in Si/SiGe QWs with varied widths and growth conditions.
"Detuning Axis Pulsed Spectroscopy of Valley-Orbital States in Si/SiGe Quantum Dots," E. Chen et al., Phys. Rev. Applied, 15, 044033 (2021). (arXiv)
Low-field T2 in exchange-only qubits in the absence of magnetic field gradients results from electrical quadrupole effects from the 73Ge nuclei.
"Magnetic Gradient Fluctuations from Quadrupolar 73Ge in Si/SiGe Exchange-Only Qubits," J. Kerckhoff et al., PRX Quantum, 2, 010347 (2021). (arXiv)
Optimizing the coupling between a triple-quantum-dot qubit and a microwave resonator.
"Resonant exchange operation in triple-quantum-dot qubits for spin-photon transduction," A. Pan et al., Quantum Sci. and Tech. 5, 034005 (2020). (arXiv)
We describe an excited-state spectroscopy technique which directly measures singlet-triplet energy splitting and demonstrate this technique on a Si/SiGe double-dot, finding the singlet-triplet splitting to be highly tunable.
"Spin-Blockade Spectroscopy of Si/SiGe Quantum Dots," A. M. Jones et al., Phys. Rev. Applied 12, 014026 (2019). (arXiv)
Demonstrating randomized benchmarking of a triple-quantum-dot qubit in Si with proper treatment of leakage out of the encoded subspace.
"Quantifying error and leakage in an encoded Si/SiGe triple-dot qubit," R. W. Andrews et al., Nature Nanotechnology, 14, 747 (2019). (arXiv)
A proposal for making a fault-tolerant logical qubit out of a linear chain of quantum dots using a minimum of hardware and control resources.
"Logical Qubit in a Linear Array of Semiconductor Quantum Dots," C. Jones et al., Physical Review X, 8, 021058 (2018). (arXiv)
A proposal for entangling electrically controlled arrays of quantum dot qubits with flying photonic qubits.
"Reduced Sensitivity to Charge Noise in Semiconductor Spin Qubits via Symmetric Operation," M. D. Reed et al., Physical Review Letters, 116, 110402 (2016). (arXiv)
Developing appropriate heterostructure stacks for highly performing silicon qubits.
"Metamorphic materials for quantum computing.," P. Deelman et al., MRS Bulletin, 41(3), 224 (2016).
Optimizing information transfer in faulty quantum networks.
"Isotopically enhanced triple-quantum-dot qubit," K. Eng et al., Science Advances, 1, e1500214 (2015).
Demonstration of an improved gate and doping architecture for silicon qubits.
"Undoped accumulation-mode Si/SiGe quantum dots," M. G. Borselli et al., Nanotechnology 26, 375202 (2015). (arXiv)
First demonstration of coherent single-spin control in a Si/SiGe heterostructure.
"Coherent singlet-triplet oscillations in a silicon-based double quantum dot," B. M. Maune et al. Nature, 481, 344 (2012).

Selected Collaborative Publications

We demonstrate a readout visibility greater than 99% and average single-qubit gate fidelities above 99.95% in a single-spin Loss-DiVincenzo (LD) qubit
"High-Fidelity State Preparation, Quantum Control, and Readout of an Isotopically Enriched Silicon Spin Qubit," A.R. Mills et al., Phys. Rev. Applied 18, 064028 (2022). (arXiv)
Demonstrated method for efficient loading of atoms into portable cold-atom microsystems.
"Active stabilization of alkali-atom vapor density with a solid-state electrochemical alkali-atom source," S. Kang, R. Mott, et al., Opt. Express, 26, 3696-3701 (2018).
Electron spins in silicon quantum dots are excellent qubits because they have long coherence times and high gate fidelities and are compatible with advanced semiconductor manufacturing techniques.
"Coherent spin-valley oscillations in silicon," X. Cai et al., Nat. Phys. (2023),

2025 APS March Meeting Presentations

"Dynamical Decoupling in Triangular Exchange-Only Spin Qubits, " Garrett Bimstefer (MAR-S34)
"Coherent Control of a Triangular Exchange-Only Spin Qubit," Edwin Acuna (MAR-S01)
"Measuring silicon spin qubits with an open-source FPGA based qubit controller," Abbie Wessels (MAR-Q01)

2024 APS March Meeting Presentations

"Fabrication and characterization of multi-rail Si/SiGe exchange-only spin qubits in the SLEDGE architecture," Kate Raach (S46.7)
"Automated Tuning of Interdot Coupling for Pauli-Spin Blockade Readout," Raj Katti (T46.3)
"Quantum Network Component Development on the 4H-Silicon-Carbide-on-Insulator Platform," Brett Yurash (K13.4)

2023 APS March Meeting Presentations

"Quiver: quantum dot device control software," Ian Jenkins (A74.2)
"A language-oriented approach to exchange-only silicon dot qubit software," Robert Smith (F70.8)
"Towards an Exchange-Only Compatible Spin-Photon Interface in Si/SiGe," Nathan Holman (Q74.2)
"Implementing universal control in encoded exchange-only Si/SiGe spin qubits," Ari Weinstein (Z74.1)
"Magnetic gradient fluctuation compensation during universal control of a Si/SiGe exchange-only qubit," Teresa Brecht (Z74.2)

2022 APS March Meeting Presentations

"Exchange-only CNOT Using the SLEDGE Quantum Dot Architecture," Matthew Reed (B39.1)
"Methods for Automatically Tuning Quantum Dot Arrays in the SLEDGE Architecture," Reed Andrews (W39.1)
"Reduced Disorder and Opportunities for Scalable, 2-Dimensional Gate Array Design Using the SLEDGE Architecture in Si/SiGe Exchange-Only Qubits," Michael Jura (D39.8)
"Theoretical Constructions of Exchange-Only Entangling and Leakage Control Gates," Thaddeus Ladd (S36.1)
"Analysis of Randomized Benchmarking with Realistic Noise," Bryan Fong (G35.9)
"Observation of Anomalous T1 Relaxation During Exchange in Si/SiGe Spin Qubits," Edwin Acuna (G39.7)
"Configuration Interaction Modeling of Si Resonant Exchange Qubits for Spin-Photon Coupling," Sam Quinn (F39.5)
"Quantum Characterization of 6-dot Exchange-Only Qubit Arrays in the SLEDGE Architecture," Nathan Holman (Z39.12)

2020 APS March Meeting Presentations

"Quantifying High-Fidelity State Preparation and Measurement in Triple-Quantum-Dot Qubits," Jacob Blumoff (R38.1)
"Full Permutation Dynamical Decoupling in an Encoded Triple-Dot Qubit," Bo Sun (L17.8)
"Theory of Pulsed Spectroscopy in Quantum Dots: Interdot Dynamics," Andrew Pan (F17.7)
"Pulsed Spectroscopy of Si/SiGe Quantum Dots: One- and Two-Electron Valley-Orbit Excited States," Catherine Raach (F17.8)
"Correcting Distortion of Base-band Exchange Pulses in Quantum Dot Qubits," David Barnes (L17.10)

Contact

Email: quantum[at]hrl.com