A Brief History of Superconducting Quantum Computing | Steven Girvin

[@atharvbhagya4317]

these are the guys that change the world.

[@ahnafakifalvi6519]

These videos from qiskit featuring peter shor, benett, girvin are so amazing.It really provides a meta level view and insights from the inventors themselves. We need more videos like this in every field tbh. Even the ambience , soothing tones of the narrators ,setups and even the sly humors are amazing. These videos will also have really high pedagogical value in the future. Qiskit please make more videos like this

[@joebowbeer]

02:26 this requires the spectrum to be _anharmonic_ 03:54 synthetic atoms vs natural atoms 05:58 Josephson effect 09:14 Tony Leggett 11:44 John Clarke, Michel Devoret, John Martinis 15:10 Cooper-pair box 17:43 Yasunobu Nakamura 20:20 Saclay group 22:18 Hans Mooij 23:05 Phase qubit 24:13 Transmon qubit 26:05 Qubit lifetime 26:30 Coherence time 27:30 Quantum-limited amplifiers 29:01 Quantum Electrodynamics (QED)

[@PhysConcept]

Professor Grivin...A genius mind explaining an elusive concept in a very comprehensible way. Indeed, Feynman said it rightly that if you completely understand an idea then you can clearly explain it to others. Thank you Qiskit.

[@johnramirez5032]

Thanks im a regular guy who has a little better understanding in the subject. I think the way he spoke. Really was logical and percise . I think quantum physics is a window into reality. I dont understand it but i still try.

[@rustybolts8953]

Fantastic! Don;t fully comprehend yet but working on it. Thank you...

[@jserien08]

Thanks to this video, I finally understood what the other KZbin channels about Quantum Computing are trying to explain with great difficulty. Thanks Professor!

[@Jajaho2]

A very good overview and even I as a mere engineer could grasp some things. Amazing job, thank you!

[@RockCoffins]

I have come up with a very brilliant method of producing, observing, storing and controlling the state of information of a Q-Bit. Theoretically, I can produce millions of Qbits which can be observed quite easily. Without the need of electron microscopes or cryogenic refrigeration. The only thing I need is someone who knows how to write the program that uses quantum algorithms. As for bringing my quantum computer to an interface of a classical computer, what I need is a software engineer. To create the program for the interface.

[@codyfan4070]

Man Girvin really had to do folks from California like that 5:01

[@kosterix123]

this is fantastic. finally something useful.

[@alexmanners1540]

It must be pretty interesting to study relativistic effects using quantum circuits

[@muskankushwah2256]

It was super amazing , just mind boggling!

[@Pingu_astrocat21]

amazing video. Thank you for uploading :)

[@Wheezr]

i had an opportunity to meet this amazing man and the first thing i said to him was "what's your name?" a shame i will never live down

[@qiskit]

Not to worry, Steve Girvin is not only brilliant, he is a very kind man and I'm sure he didnt mind.

[@Wheezr]

a physics professor, peter persans, was at the same table, and he had to come up to me later just to make sure i knew who i was being so audacious at

[@oosmanbeekawoo]

(´ ⊙◞⊱◟⊙ ｀) The quality of your content and at _that_ rate is seriously baffling!! Four Super Videos in a Day! 🥴

[@curiodyssey3867]

Well....they do have VAST resources

[@Major-Steve]

Layman here. I think what confuses most people like me is the term “observe”. If I want to observe an animal creeping around in my backyard at night I’ll need to bombard it with photons. When I do, it might change its behavior.

[@HPwned]

Your question is really deep . I'm not sure that I can answer all of it, but I will try to give some insight. To observe/measure a quantum state in an experiment, the experimenter must do something to the quantum state that causes it to react in a detectible manner. I think the phase qubit example at 23:07 is a great example of this. In the experiment, Martinis was able to drive the |1> state of the qubit to a higher energy level so that it would tunnel out of the system, producing a detectable voltage response. If he drove the qubit and measured a voltage response the qubit was in state |1>. If no voltage was detected the qubit was in state |0>. This measurement is destructive, however, as any qubits in |1> have now tunneled out of your qubit and their information is lost. This changes your system. Lets say you have a state that is in a superposition (for simplicity sake let's say that it has some probability of being in |0>, and some probablity of being in |1>, though this definition for superposition is very wrong), when you measure the state, this superposition will collapse. You will either get |1> with probability and lose your qubit, or you will get |0> with probability . If you measured the qubit in |0> then measure it again and again you will always get |0>. You have changed the quantum system from a superposition to just the state |0> by destroying the qubit if it was in state |1>. For the other part of your question, which I interpret as: why don't these quantum ideas of measurement induced state collapse appear visible on the human scale? I will say that to my understanding quantum phenomena should be possible on all length scales, the problem is that quantum coherence (the ability for a state to maintain its entanglement and superposition) is very fragile and rare for large systems. The animal in your backyard has an unfathomable number of atoms all behaving randomly. The probability of all of those atoms randomly behaving in a coherent fashion is exceedingly low compared to the sea of states where they are incoherent. If they were miraculously coherent, that coherent state may only last for an imperceptible amount of time (for our eyes) due to all of the different ways that the state could decohere. I'm a bit shaky on this part of the explanation and would implore you/anyone else to try out Feynman's QED for some more insights on this idea. If anyone else has insights or corrections to what I said, I welcome them :)

[@LydellAaron]

2:25 system spectrum needs to be "anharmonic." Interesting.

[@Jeraestone]

My Approach to this "Exqiskit Field" : : is to Patietly Absorb as many Processes as I can Fit into and over a Cup Of Te // Tae // Tee // Tay ?? I think I am making Tea or is it Making me ?? Its all so Great to Listen into, even though I have No Idea What Part I can play in this 'Spin Doctors' (( Girvin)) World ...Perhaps he Needs a Teabuoy ? or someone to Light The Fire Behind him Love the Tongs and Pokers but whats with the Ikea Lights? Super Cool Tok !

[@sathyashiva3363]

Nice

[@rustybolts8953]

Five Schrodinger's cats! The imaginary animal rights activist will be right after you. Thank you again Dr. Steven Girvin.

[@ButchMarshall]

I wish I had someone to talk out my naive understanding of this with - will you help KZbin?! Are all these artificial qubits basically observing a quantum tunneling effect through detecting a voltage change in the josephson junction? But how is this useful for doing computation like in a classical computer?! Is the voltage change/ tunneling related to the computation result?

[@nabaneetsharma451]

Josephson junction helps in creating a nonlinearity in the circuit that results in making anharmonic quantum levels which can thus be used as qubits. The reason behind the tunneling is quantum mechanical. Read up on superconductivity.

[@ReumiChannel]

4:06 you mean natural atoms?

[@frankjohnson123]

Yes, this confused me at first. The channel should correct it with an annotation or something.

[@spacekid1000]

it will also be able to simulate a brain, may be big but it can when created as such, maybe even advanced ai, are they just sitting there equating the next sale at hm?

[@emdadsami]

🎯 Key Takeaways for quick navigation: 00:00 📜 *Superconducting qubits store quantum information and face the challenge of conflicting constraints: isolation for long coherence times and the need for rapid state changes.* 04:11 ⚛️ *Choice between natural atoms/ions and synthetic atoms (superconducting qubits); the latter, though complex, offer engineering advantages like individual design and compatibility with electronic circuits.* 06:39 🔗 *Josephson effect in superconductors, discovered in the 1960s, provides a macroscopic manifestation of quantum order and forms the basis for superconducting qubits.* 12:40 🛰️ *Spectroscopy on superconducting qubits involves microwave radiation to excite transitions between quantized energy levels, enabling observation of quantum coherence.* 20:03 🔄 *Rapid change in gate voltage induces non-adiabatic evolution of quantum states (Rabi oscillations), demonstrating direct time-domain evidence of quantum coherence in electrical circuits.* 21:35 🌐 *Introduction of quantronium, a hybrid charge-phase qubit, demonstrating Ramsey interference fringes as evidence of coherence, overcoming noise in parameters.* 23:35 🌀 *Various qubit designs: flux qubit, phase qubit, and the widely used transmon qubit; progress in coherence times and high-fidelity two-qubit gates.* 28:03 📡 *Quantum electrodynamics of electrical circuits involves cavity QED, utilizing the Purcell effect to enhance qubit lifetime by controlling vacuum fluctuations.* 30:59 🤝 *Application of quantum optics and cavity QED concepts to microwave electrical circuits for quantum information processing, with personal involvement in the field's development.* 31:30 🤯 *Vacuum Rabi splitting in artificial atoms within a cavity allows observing coherent motion of one excitation.* 32:57 🚀 *Achieving strong dispersive coupling in circuit QED, even when detuned, enables distinct frequency shifts with the addition of a single microwave photon.* 34:22 🛠️ *Circuit QED leads to the development of the first all-electronic quantum processor in 2009, inspiring the current industrial systems with 50-60 qubits.* 36:28 🤖 *Quantum error correction progresses, with the Schrodinger cat code in 2016 reaching the break-even point, and recent experimental realizations of Gottesman-Kitaev-Preskill code.* 37:59 🌐 *Andreas Wallraff entangles qubit systems separated by five meters using a cryogenically cooled waveguide, achieving a state transfer fidelity of about 80%.* Made with HARPA AI

[@lacychrist4320]

Did he just use the Floo Network to come to guide us from a Temple of Wizardry?

[@abhaysmith1117]

Anyone else thinks the guy looks like walter White?

[@adamaunya69]

You're goddamn right

[@billystrickland1778]

Sponsered by HP

[@faizalqorni3611]

John McAfee if he studied quantum physics

[@albertvandrejer5003]

what do you mean with that?

[@tricky778]

Did that guy just virtue-signal at the start - how can we trust what he says?

[@nashvillain171]

He did, indeed. Completely unnecessary.

[@DMahalko]

It's nice to see that the rational thinking person is wearing a mask to protect himself from coronavirus. He is much more important to the world than some random derp critiquing him for demonstrating that he is a rational thinking person.

[@nashvillain171]

@@DMahalko If that's what masks actually did, I might halfheartedly agree with you.

[@tricky778]

@@DMahalko no, he took it off

[@laurenth7187]

I will make it even briefer : Between all your quantum component, you have to use connections, which are not allow to carry information faster than light. So all your superfast devices are useless, that why the main improvement one do is a shrinking process. A brief history of useless research.

[@livlanes]

this isn't how quantum computers work.

[@laurenth7187]

@@livlanes they do not work at all, like nuclear fusion and much more, it's only to get funds.

[@folfol3008]

your comment is a brief history of your useless brain

[@quantumgirl3047]

Right, everyone whose research is on quantum computing is in it for the money. We all know how much money is in academia, ask any of these rich grad students!

[@brendawilliams8062]

Knowledge can look stupid and still be bigger than brilliant in terms of progress. My thought was the cosmos problem and you might push the no poles thing with a crystal.

[@georgejo7905]

did not Claude shannon really start all this .Information entropy wherein measurement is just a source of noise that reduces bndwidth.

[@bussi7859]

Crap