3 ms·
Peter Shor would like to have a word with you...
by pugfugly 28d ago
Peter Shor would like to have a word with you...
- catlifeonmars 28d agoShor's algorithm needs technology we still don’t have. Get back to me when we can have more than a handful of qubits reliably compute things.
- adastra22 28d agoWe only need the ability to make make 1 qubit with indefinite reliable / fully error corrected state. Quantum interconnects would allow for these to be connected into arbitrarily large quantum computers.
- arcticbull 28d agoSo we only need to invent actual quantum computers. Got it, easy.
- smallerize 28d agoYes, but since R&D and funding are in a feedback loop now (promising results -> more money -> better results etc), it might only take a couple more years to get there. https://arstechnica.com/science/2026/06/amazon-quera-promise-useful-quantum-error-correction-by-2028/ https://arstechnica.com/science/2026/06/amazon-quera-promise...
- adastra22 28d agoIt's more akin to "we only need to make reliable transistors to make classical computers." With the invention of the planar transistor, going from 1 transistor to 100 or 100k was not that big of a step, comparatively.
- heavenlyblue 28d agotransistors are local unit, qubits are not
- adastra22 28d agoTransistors connect to other transistors, directly or in switched arrangements. Qubits can be connected to other qubits likewise. E.g. a single photon emitter next to a nuclear spin qubit that can send an entangled photon through a beam splitter in a photonic switch, routing that entangled pair through fiber optic cables to other qubits where a combination of electric fields, filters, and occupied energy levels cause gate operations to be applied during absorption & re-emission. Except for the long-lived, error-corrected qubit, everything I described there is off-the-shelf commercial technology.
- fsh 28d agoPhotonic quantum interfaces typically operate at glacial speeds and with terrible fidelities. There is a lot more missing than good qubits.
- Dylan16807 28d agoIt's really really easy to eliminate noise in a digital system of transistors. For analog systems with subtle values, I would say we still can't arbitrarily scale that up with transistors. And quantum is like analog but far worse.
- tgv 28d agoBut those cannot exist, can they? Nature seems really opposed to the realisation of ideals.
- adastra22 28d agoMy company is making them. You just need to have a sufficiently resilient surface code, which means a single device with millions of physical qubits (the standard brute-force approach) or use a qubit architecture that is intrinsically noise-free by comparison, and only needs 15-50 physical qubits (what my company is doing, and our competitors). The industry as a whole is probably only a few years away from achieving this, in some form. A "perfect" or "indefinitely stable" qubit sounds impossible. But so would a DRAM cell to an electrical engineer in the 40's. A DRAM cell continuously refreshes to maintain state, and as a result a single bit in RAM can have a mean time to failure measured in geologic time. Likewise a quantum error correction algorithm with a sufficiently large factor, driven continuously, will maintain qubit state indefinitely.
- fsh 28d agoElectrical engineers in the 1940s already had "infinitely stable" memory in the form of delay lines and Williams tubes. Quantum error correction is incomparably more difficult than using digital bits.
- shaaaade 28d agoWhy is it that every time I read about quantum computers, fusion, and high energy density batteries, the word "just" seems extremely load-bearing, but results are like just, nowhere to be seen
- catlifeonmars 28d agoWhat does indefinitely stable mean?