HearingTheQuantum

Trying to forecast the future of quantum computing be like

The sweet thing about a really snowy day is that people somehow start saying "hello" to each other when crossing on the street

Move fast and break things💪🛥️

A similar method allows us to tune two-qubit gates on a per-zone basis. We measured the Bell states in the central zone with high precision (though all zones seem identical for all we know), recording a record 99.97(1)% fidelity, and impressive stability over 60 hours. 11/n

Not only is this method chip-integrated, it also works *really* well. In the paper, we perform 1-qubit gates in any zone with < 1e-5 error and ~ 1e-6 level crosstalk. And it's really scalable - for all we know, we can just keep adding zones and they will all work the same! 10/n

which allows us to make the Rabi flops either very slow (qubit 'hidden') or very fast (qubit 'active'). We can do it very flexibly on a per-zone basis, allowing us to e.g. make an X gate in any subset of zones in the processor. 9/n

Of course, it's not enough to do gates everywhere, we also need to modulate them locally. But this can be done electrically by fine-tuning the ion position above the current-carrying trace. In our experiment, we apply voltages applied to DC electrodes to move the ion along y 8/n

What's neat about this method is that you can drive a lot of qubits from one trace, i.e. instead of building another laser lab every time you want to add a few qubits, all you need to do is make the on-chip trace a little longer. In the end, your QC looks simply like this 7/n

At @OxfordIonics we decided to follow a different, more scalable paradigm. Our ions are also trapped above a chip, but quantum gates are driven not by lasers, but by AC currents running through chip traces. For background see e.g. nature.com/articles/nature10… 6/n

Case and point: arguably the most powerful QC in the world, @QuantinuumQC's H2, has 56 qubits but only 4 gate zones (circled) that the qubits are sequentially placed into. This is because scaling free-space optics is a PITA 4/n

On the other hand, trapped-ion qubits have really low noise: >99.9% fidelity, >1h coherence time etc. But all the commercial trapped-ion systems rely on free-space optics to deliver high-power control beams, which is really tough to scale... 3/n

Taking a step back, what's nice about solid-state QCs is that they look like computers. I mean, it's essentially a standard chip with qubits built in, so it feels it should scale, right? 🤣 However, chips are noisy environments, so the qubits decohere really fast... 2/n

To celebrate the new result from the trapped ion QC team at @ETH_en, I ask: are trapped-ion quantum computers really thaaaat hard to scale? Blog post: m-malinowski.github.io/2024/… Answer: no, they're not thaaat hard to scale Paper: arxiv.org/abs/2401.18056

Quantum computing industry, particularly the quit subset

😞🐶⚛️

Ladies and gentlemen, for the third time ever, the first 1000-qubit quantum computer! Third time lucky?

Inspired by my favourite fictional talk show "Big talk", here is my personal take on how to build the quantum workforce of the future: m-malinowski.github.io/2023/… And here is "Big talk": youtube.com/watch?v=o2m0HHcy…