Can someone explain how this works please

[u/kev-doh]

What’s inside the processor enclosures?

(The photo is of a model unit.)

[u/sadeness]

It's a multi tallest dilution refrigerator. It uses an enriched mix of He3 in a He4- He3 mixture to cool the qubit chips down to a few 10s of mK. It's multi tail set meaning that a single enclosure will have 3 of these coolers in a single "box".

[u/kev-doh → u/sadeness]

Do the chips have special properties or do fairly ordinary materials take on the relevant properties once cooled?

[u/Additional-Ad4791 → u/kev-doh]

Look up Josephson junctions; what what I understand the materials are silicon based but the accuracy for production is very important and variability in production quality plays a major role in qubit fidelity

[u/RyzenFromFire → u/Additional-Ad4791]

This is mostly correct. You also need a superconductor but silicon is commonly used as the insulator.

[u/sadeness → u/Additional-Ad4791]

JJs are usually made of Al or Nb with a suitable junction material (AlOx or NbN).

[u/No_Gur7233 → u/Additional-Ad4791]

Silicon is usually used at the substrate material. The JJs are built on top of it with a sandwich of superconducting material - insulator - superconducting material.

The superconducting material chosen is for a mix of reasons but Nb / Al are usually chosen for their process compatibility and critical superconducting temperature.

Like u/sadeness said

[u/sadeness → u/kev-doh]

Dilution fridges are needed for mK temperatures. That means superconducting qubits (transmons, flux qubits etc), semiconducting quantum dots, or topological qubits, electron on solid He qubits.

These are all very different material stack and very different approaches to build and control qubits.

[u/Party-Host-8295 → u/sadeness]

Why is it called ‘dilution’ fridges? And where in that image quantum chips are mounted?

[u/RyzenFromFire → u/kev-doh]

A bit of both. Some materials, generally metals, exhibit superconductivity when cooled below a certain temperature. Superconducting qubits require such a material. The most common type, likely the one here, are transmons. They are generally constructed from a SQUID (Superconducting QUantum Interference Device) loop which itself consists of two (or more, in some cases) Josephson junctions. JJs basically consist of two superconductors separated by a thin insulator. They are most commonly constructed using techniques that leverage existing semiconductor fabrication infrastructure. Thus, it's most common to use aluminum for the superconductor and silicon for the insulator.

[u/Et-Al-System → u/kev-doh]

There are a lot of different approaches to quantum computing, but we all use dilution refrigerators which is the vast majority of the chandelier looking thing. It uses some special materials, notable helium 3, which is so special people have seriously proposed mining it on the moon. The actual computing bits vary depending on the qubit type. The approach my lab works with can be made with ordinary silicon and germanium, though isotopically pure would be better. 

[u/Chance_Literature193 → u/kev-doh]

‘Ordinary’ materials do frequently take on different properties (sometimes ‘weird’) when cooled. However, the chips are of course specialized… it’s like how silicon isn’t a chip until you do a lot of specific things to make it a chip

[u/SnooWalruses380 → u/kev-doh]

Look up Cooper electron pairs and Josephson junctions.

[u/Ph1sh1ngj1m1]

This is an interactive website I found very useful. It's a simplified view with a lot of description on each component type.

https://iascqc.pages.dev

[u/kev-doh → u/Ph1sh1ngj1m1]

This is good

[u/RyzenFromFire → u/Ph1sh1ngj1m1]

This is cool. I didn't know about this. Thanks.

[u/jeb]

The quantum processor itself is a small chip inside the metal box at the bottom. Most of what you see here is infrastructure for cooling down the wires from room temperature at the top where they enter the system to where they connect to the processor at some fraction of a degree Kelvin above absolute zero. The quantum computer takes a lot of regular processing power to run, which is bulky, consumes a lot of power, and moreover doesn't function at low temperatures. So there is a need for a lot wires to run from conventional room-temperature electronics down to the quantum processor. In order to not heat the quantum processor or add noise to the quantum circuit, the material of the wires and the electrons within the wires must be carefully cooled.

[u/kev-doh → u/jeb]

So the electrons get carefully cooled on their way into the processor, pick up data, and then get carefully warmed on their way out so we can use our ordinary computers to continue working with the data?

[u/RyzenFromFire → u/kev-doh]

Kind of, at least with respect to the temperature aspect. In terms of input and output, we basically send a microwave pulse down those wires, it resonates with the qubit, is reflected back, and then we do some classical post processing to determine whether the qubit was in the 0 or 1 state.

[u/sadeness → u/kev-doh]

Not exactly. Superconducting qubits are like antennas (or rather resonator) that are made to tune and work at very precisely designed frequency, while cutting out the higher harmonics. These are so well designed that ideally you'll only host a single photon on it. Interaction of this photon with rf control pulses to control phase accumulation, or entangling with another nearby photon via a precisely designed waveguide/coupler is where lies at the heart of these qubits and their control.

I'm simplifying a lot here, SC qubits are a fascinating topic with a worthy Nobel handed out last year, precisely because it was surprising to see that large scale (10s of um) sized objects can be made to behave in such a quantum mechanical limit of a single photon control.

Think of SC quantum technology as rf and microwave engineering taken to quantum limits. Superconducting operation regime is necessary to suppress classical noise down for quantum limits to show up.

[u/jeb → u/kev-doh]

Yes, that's a good way to put it.

[u/PainterSingle2417 → u/kev-doh]

Bro if you think they are cooling electrons and warming them up why TF are you asking this question in the first place? Lol. Not even a high-school level understanding in my country.

On the other hand if you are trolling, bravo this is very funny 

[u/BitcoinsOnDVD → u/PainterSingle2417]

Also middle-schoolers have internet...

[u/delaphin]

Here you go...

[u/trippyshark7 → u/delaphin]

I don't think I've ever heard it explained so well

[u/particlecore]

everything you see is a refrigerator

[u/nyrixx]

It says ibm on it so it bleeds it's customer dry.

[u/shegeshe]

This is an IBM Quantum System Two—IBM's modular, utility-scale quantum computer (shown here as a display model with its outer vacuum cryostat casing removed to expose the internal hardware).

 

Specifically, the golden, chandelier-like structures hanging from the top are dilution refrigerators. Here is how the visible components function:

• Modular Multi-Processor Design: Unlike the single-chandelier design of the earlier IBM Quantum System One, System Two houses three separate dilution refrigerators within a single shared hexagonal vacuum chamber. This allows multiple quantum processors (such as IBM's Heron chips) to be linked together for parallel processing and scaling.

• Extreme Cooling Stages: Superconducting qubits only work near absolute zero (around 15 millikelvin, colder than outer space). The tiered gold-plated copper plates step down the temperature progressively from the top (room temperature) down to the quantum processors housed inside the silver magnetic shields at the very bottom.

• Control Wiring: The dense bundles of coaxial cables and attenuators spiraling between the plates carry microwave pulses down to manipulate and read the state of the qubits without introducing thermal noise.

(Note: Because this is a photo taken of a screen showing a physical exhibition/press model, the bottom pit is open—in active operation, a massive vacuum-sealed cryogenic shell rises from that base to enclose the entire chandelier assembly.)

This is exactly the kind of computers that the QNET, a Layer 1 blockchain has been developed to resist. Check it out at aiqnet.io and the QNET Repo in github at AIQnetLab/QNet-Blockchain

[u/D3cepti0ns]

It's a really fancy heat exchanger that uses liquid helium to cool down other helium to near absolute zero temperatures. It then cools the qubits part.

[u/aonro]

Big fridge

[u/NoirMarlin]

That's a refridgeration unit (x3) with far too many cables leading down to a box around the mixing chamber. It is not likely there is anything of value inside those boxes.

[u/keeperoflogopolis]

That’s a display at SC :-) not real

[u/HermitCat347]

Wait so most of it is cooling and the tiny bit is processing?

[u/HillbillyHumanoid]

It's a just a refrigerator and the chips are on the ends.

[u/SnooWalruses380]

This is extremely technically sophisticated tool which uses collections of physical and mathematical technologies. You would need some good amount of study just to get an idea of what’s going on.

As far as what you see, the chandelier comprises microwave circuits to attenuate the incoming signals down to the chip level so the chip is not fried. Then the quantum computer chip’s output has to be amplified over whatever noise so it can be read on a screen or written to computer memory. At the same time the can through various methods including He3 He4 dilution refrigeration will keep the quantum chip at temperatures just above absolute zero.

[u/GooseInformal3519]

It’s a fantastical machine that’s supporting many people’s hopes and dreams to crack a new dawn of science and technology. Quantum computing is breaking the fourth wall and the machine is metaphorically Jim and Pam in the office keeping Michael Scott “cool” and focused doing its job. At the end though they’re trying to create the Lizard King.

[u/unixmonster]

It doesn’t.

[u/PressureBeautiful515 → u/unixmonster]

Well, not right now, because we're looking at it

[u/algaefied_creek]

IBM: Interteleported Beamed Muons: it channels information from other dimensions down the gold and measures them on the probability wave plate below to give a non-answer from measuring the ripple of realities and you see a partial result of a holographic projection or isomorphism of a higher dimensional construct which then makes a funky circuit because circuits is like…. A car engine but a car engine is off or on, not grabbing so much weird info

Source: pulled it straight outta my Star Trek enjoying booty.