CQI Seminar: Will Schober
by William Schober
Dear friends,
Next Tuesday 30.4 at 11:00 in D1.13 we'll have a forum on some work I'm planning to submit for publication. It's a method of calculating using only circuit equivalences, with potential application to circuit optimization/transpilation. Title and abstract below. I'll show the basics and then open up the floor for feedback from you guys!
Join us online at https://meet.jit.si/CQISeminarTalks
Warmly,
Will
Title: Quantum circuits as a self-contained graphical language
Abstract: Quantum circuit diagrams can be axiomatized as a standalone graphical language. Once imbued with a set of rewrite rules, circuits can be used to compute graphically. This provides a way to transform one circuit into another without converting to a more powerful graphical language like ZX-calculus, potentially circumventing the #P-hard 'circuit extraction problem' faced by ZX-based circuit optimizers. I present a preliminary list of rewrite rules for circuit diagrams. Depending on time and interest, I can show example calculations at the end.
4 days, 20 hours
CQI Seminar: Charles Bédard
by William Schober
Cari amici,
Tomorrow at 16:00 we'll have an informal and improvised presentation by Charles Bédard on the subject of Bell locality, followed by a discussion (W to C: informal and improvised, aka a forum? Just the way we like it 🙂). Charles is currently somewhere in the woods of Québec so we'll meet virtually at https://meet.jit.si/CQISeminarTalks. Feel free to join us physically in D4.01. Title and abstract below.
Warmly,
Will
Title: Bell from Everett and Heisenberg
Abstract: I’ll discuss how an apparently science-fictional local-realistic explanation of Bell violations (by Raymond-Robichaud) can in fact be obtained in the Heisenberg picture of unitary quantum theory. I hope that the discussion will ramify into connected topics, such as Everett’s basic idea, the clash between Einstein’s and Bell’s locality, states versus descriptors, the classical quantum versus the quantum classical, and more.
1 week, 1 day
CQI Seminar 17.4, Will Schober
by William Schober
Cari amici,
We were only able to get through half of the material in this week's seminar on quantum error correction, so we'll pick it up again next Wednesday, 17.4, at 15:30-16:30 in D1.14 (afternoon this time to accommodate a listener across the Atlantic). I'll go through the stabilizer formalism and show a few examples of codes currently in use in today's quantum computers.
Join us in person or online at https://meet.jit.si/CQISeminarTalks
Warmly,
Will
Title: Quantum error correction 101, continued
Outline:
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Stabilizer formalism
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CSS codes (ex. [[7,1,3]] Steane code)
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Surface codes (ex. [[25,1,5]] Toric code)
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Color codes (ex. [[8,3,2]] Cubic code)
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LDPC codes
2 weeks, 5 days
CQI Seminar 10.4, Will Schober
by William Schober
Cari amici,
This Wednesday, 10.4, at 11:00 in D1.14 I'll give an introductory talk on quantum error correction. It's a hot topic these days so I figured it would be good to know something about it. I've learned the basics and will go through them in this talk, focusing on examples of error correcting codes currently in use in today's quantum computers.
Join us in person or online at https://meet.jit.si/CQISeminarTalks
Warmly,
Will
Title: Quantum error correction 101
Rough outline:
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Classical linear codes
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Generator matrices and parity check matrices (ex. [3,1] repetition code)
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Dual codes (ex. [7,4] Hamming code)
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Quantum difficulties: no cloning, measurement, and continuous errors?
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Stabilizer formalism
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Stabilizers and normalizers (ex. [[3,1,1]] Bit flip code)
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CSS codes (ex. [[7,1,3]] Steane code)
*
Surface codes (ex. [[25,1,5]] Toric code)
*
Color codes (ex. [[8,3,2]] Cubic code)
*
LDPC codes
3 weeks, 2 days