Presented at the Q2B Silicon Valley conference in December, 2023

1. QuEra’s Path to Fault-Tolerant
Quantum Computing
#TheBestWayToQuantum
December 2023
Yuval Boger,
info@quera.com

2. Complex Algorithms
on 48 Logical Qubits
Announcing a Major Milestone
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“Logical quantum processor based
on reconfigurable atom arrays”
Bluvstein (Harvard), et al.
ArXiv link: https://arxiv.org/abs/2312.03982

3. In experiments led by Harvard University in close
collaboration with QuEra, MIT, and NIST/UMD,
researchers successfully executed large-scale
algorithms on an error-corrected quantum
computer with 48 logical qubits and hundreds of
entangling logical operations.
Announcing a Major Milestone
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4. Collaborators and Supporters
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5. Key Achievements
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Using [8,3,2] code blocks, implemented a complex sampling circuit
with 48 logical qubits, 228 logical two-qubit gates, and 48 CCZ gates
Improvement of a two-qubit logic gate
by scaling surface code distance from d = 3 to d = 7
Preparation of color code qubits with break-even fidelities
Fault-tolerant creation of logical GHZ states,
operation of 40 color-code qubits
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Note: These experiments were performed at Harvard and led by a Harvard team
with collaborators from QuEra, MIT, and others.

6. Error Rate is the Fundamental Issue
What limits our ability to perform longer computations?
Number of qubits (100s):
Good
Number of steps:
A few thousands
2-qubit fidelity (99.5%):
~200 steps
Fundamental Limits
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Ref: Evered (Harvard) et al., Nature 622 (7982), 268–272 (2023)

7. Logical Qubits
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Physical qubit error rates are insufficient for useful algorithms
“State of the art” 99.9% means one error in each 1000 operations
Logical qubits use multiple physical qubits to protect information
The ratio of physical to logical qubits depends on the QEC code used
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Paper:
Ref: Bluvstein (Harvard)
et al., Nature 2023

8. Code Distance
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A code distance indicates how many errors the code can correct
Distance d can correct (d−1)/2 errors
Examples
d=3 can correct 1 error, d=5 can correct 2 errors, etc.
Larger code distances require a larger number of physical qubits
Note: Code distance 2 can detect an error but not correct it
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9. Key Achievements
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Using [8,3,2] code blocks, implemented a complex sampling circuit
with 48 logical qubits, 228 logical two-qubit gates, and 48 CCZ gates
Improvement of a two-qubit logic gate
by scaling surface code distance from d = 3 to d = 7
Preparation of color code qubits with break-even fidelities
Fault-tolerant creation of logical GHZ states,
operation of 40 color-code qubits
9t
Note: These experiments were performed at Harvard and led by a Harvard team
with collaborators from QuEra, MIT, and others.

10. About QuEra
We built and are operating the world’s only publicly-
accessible quantum computer based on neutral atoms.
We have a clear path to the “holy grail” of quantum
computing: a large-scale, error-corrected device.
We productize innovations from QuEra and our
MIT/Harvard collaborators at record speed.
Dozens of organizations already use our quantum
computer.
Based in Boston, we employ 40+ scientists and engineers
from Harvard, MIT, and other top-tier institutions.
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11. Built on Outstanding Scientific Foundations
Mikhail Lukin
Professor of Physics.
Pioneer in quantum simulation
MacArthur ‘genius grant’ fellow
Vladan Vuletic Dirk Englund
Alex Keesling Nathan Gemelke
CTO, co-founder, QuEra
CEO, QuEra
Markus Greiner
Professor of Physics.
Quantum computing pioneer
Professor of Physics.
Pioneer in creating and controlling
large entangled systems
Professor of EECS.
Expert in photonics and
systems architecture
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12. Delivering a Series of Breakthroughs
12
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Top row: Academic demonstrations at Harvard and MIT
Bottom row: Commercialization activities at QuEra
Ref: Bluvstein (Harvard)
et al., Nature 2023
Ref: Evered (Harvard) et
al., Nature 2023
Ref: Endres (Harvard)
et al., Science 2016

13. 13
What Made this Possible?
Key Building Blocks
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14. Nature’s perfect qubits
We use atoms – identical, pure, and resistant to noise.
Operate at room temperature
No cryogenic cooling is required.
High 2-qubit gate fidelity: 99.5%
Beyond error correction threshold.
Neutral Atoms
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15. • 10,000 qubits
• No interconnect required
Qubit Shuttling
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Zoned Architecture
Fewer control lines
• No need for a control line to
each qubit.
All-to-all connectivity
• Storage
• Entanglement
• Measurement
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Ref: Bluvstein
(Harvard) et al.,
Nature 604 (7906),
451-456 (2023)
Video:

16. Transversal Gates
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17. Zoned Architecture
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Ref: Bluvstein et al.,
Nature 2023
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18. A 48 Logical Qubit Algorithm
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Video:
Ref: Bluvstein
(Harvard) et al.,
Nature 2023

19. Future Work: Massive Scalability
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• 10,000 qubits
• No interconnect required
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Ref: BernienLab, www.bernienlab.com

20. Join us on Jan 9th, 2024 as we Unveil our Roadmap
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https://quera.link/roadmap
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21. Welcome to the Era of
Logical Qubits
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#TheBestWayToQuantum