And what it can teach you about quantum physics

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I made this. I’m not all that proud of it to be honest.

Four quantum physicists are in a car. Heisenberg is driving like he is in The Matrix. Schrödinger is in the front seat waving at the other cars. Einstein and Bohr are in the back arguing when they get pulled over. The officer asks Heisenberg, “do you know how fast you were going?”

“No, but we know exactly where we are,” Heisenberg replies.

The officer looks confused and says, “you were going 120 km/h!”

Heisenberg throws his arms up and cries, “Great! Now we’re lost!”

The officer looks over the car and asks Schrödinger if they have anything in the trunk. …


A gentle introduction to quantum tomography

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Photo by krakenimages on Unsplash

This lecture was given as part of Quantum Computing Through Comics series on Hackaday organised by Kitty Yeung. Kitty has drawn an amazing comic summary of this lecture as well! The recording of this lecture is available on Kitty’s YouTube channel:

Who are you?

You’ve done a bit of self-study. You’ve participated in quantum technology lectures. You’ve got an awesome certificate from Kitty — and had it printed on a mug! Maybe you’ve even implemented a quantum algorithm on a cloud-based quantum computer. By all accounts, you’re a quantum coder. That’s great, because I have a problem. Someone gave me this quantum device, but I have no way of proving it really is a quantum device or what it does! …


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Welcome to Introduction to Quantum Computing. I am your guide, Associate Professor Chris Ferrie, a researcher in the UTS Centre for Quantum Software and Information. This is Lecture 8. It would probably be a good idea to have read the previous Lectures before continuing.

What did you learn last week?
Last week you were introduced to the Deutsch-Jozsa algorithm, which was the first computational algorithm to show a speed-up over any classical algorithm. You also learned about how to perform digital logic in a quantum computation and create quantum oracles.
What will you learn this week?
This week you will learn about the high-level structure of quantum algorithms and some primitives such as superposition, digital logic, phase logic, and uncomputation. With these you’ll at least be able to fake it until you make it! …

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Photo by Rhett Wesley on Unsplash

There is a magician on stage. It’s tense. Maybe it’s a primetime TV show and the production value is super high. The celebrity judges look nervous. There is epic build up music as the magician calls their assistant on stage. The assistant climbs into a box that is covered with a velvet blanket. Why a blanket? I mean, isn’t the box good enough? What a pretentious as… forget it, I’m ruining this for myself. OK, so the assistant is in the box with their head and legs sticking out. What the fuck? Who made this box, anyway? Damn it, I’m doing it again. Then — oh shit — is that a saw? What’s going to happen with that? Fuck! No! The assistant’s been cut in half! And then the quantum computer outputs the answer. Wait, what? Where did the quantum computer come from? …


Life Beyond The Flipped Classroom

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Me in mid-2020 talking to my computer screen at midnight in the hopes that it might help a student understand something about quantum computing.

This is a talk I will give at the NQN Workshop on Quantum Programming in Theory, Experiment and Classroom. My talk is about flipped learning of quantum computation. It kind of behooves me then to provide the lecture material before class. So, dear attendees, here is the structure of your pre-talk reading assignment.

1) Audience | Who are you?
2) Problem | Lighting a global pandemic under my ass
3) Solution | The U(1) Transformed Learning Model
4) Tools | Don’t reinvent the wheel — steal an 18-wheeler!
5) Implementation | What does it look like? …

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Welcome to Introduction to Quantum Computing. I am your guide, Associate Professor Chris Ferrie, a researcher in the UTS Centre for Quantum Software and Information. These are the notes for Lab 6. You should have already enjoyed Lecture 6. The syllabus is here:

In Lecture 6 you were introduced to superdense coding and quantum teleportation. We looked at the circuits and even built them with the Quirk drag-and-drop simulator. In this Lab you will build both protocols in the three programming languages you were assigned in Lab 4.

cirq

qiskit

projectq


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Welcome to Introduction to Quantum Computing. I am your guide, Associate Professor Chris Ferrie, a researcher in the UTS Centre for Quantum Software and Information. This is Lecture 7. It would probably be a good idea to have read the previous Lectures before continuing.

What did you learn last week?
Last week you were introduced to your first two quantum protocols: superdense coding and quantum teleportation. These clearly utilise entanglement as a resource to achieve a task not possible with classical bits.
What will you learn this week?
We will continue the theme of quantum advantages this week by studying the Deutsch-Jozsa algorithm. This algorithm also deterministically solves a problem which is impossible to solve via classical means with the same number of resources. …

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Welcome to Introduction to Quantum Computing. I am your guide, Associate Professor Chris Ferrie, a researcher in the UTS Centre for Quantum Software and Information. This is Lecture 6. It would probably be a good idea to have read the previous Lectures before continuing.

What did you learn last week?
In the last few weeks you completed your basic training. You now know about quantum information, how to write it, how to read it, and how to dial it up to 11 with entanglement. Entangled states were those that could not be written as product states (in any basis!). …

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Welcome to Introduction to Quantum Computing. I am your guide, Associate Professor Chris Ferrie, a researcher in the UTS Centre for Quantum Software and Information. These are the notes for Lab 5. You should have already enjoyed Lecture 5. The syllabus is here:

At this point it is time for you to put in the work. Practice not only makes perfect, but it can also make you even half-way competent! I don’t expect the former, but I will accept nothing less than the latter. So let’s get to work and make our hands cramp from bra-keting!

Quantum Rosetta Stone

I remember a physics class in undergrad where we were allowed to bring a “cheat-sheet” into the exam. We could write whatever we wanted on a single side of a Letter-sized piece of paper. The only stipulation? It had to be hand-written. By writing, over and over again, the equations as neatly and compactly as I could in preparation for the exam, I had nearly memorised every formula and even generated my own mnemonics! …


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Something I lost sight of for a long time is the reason I study physics, or the reason I started studying it anyway. I got into it for no reason other than it was an exciting application of mathematics. I was in awe, not of science, but of the power of mathematics.

Now there are competing pressures. Sometimes I find myself “doing physics” for reasons that can only best be seen as practical. Fine — I’m a pragmatic person after all. …

About

Chris Ferrie

Quantum theorist by day, father by night. Occasionally moonlights as a children’s book author. www.csferrie.com @csferrie

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