The First 6100 Qubit Array at Room Temperature

(caltech.edu)

8 points | by oldfuture 8 hours ago

2 comments

  • adrian_b 3 hours ago
    "Room temperature" here just means that the whole device is not inside a cryostat, like for superconducting devices, which is indeed what matters for reducing cost and power consumption.

    The actual temperature of the lattice of neutral atoms held in vacuum with lasers is very low, i.e. the kinetic energy of these atoms is very low, otherwise they would escape the lattice. When the lattice of neutral atoms is created, the atoms are cooled with dedicated lasers, distinct from those that control the positions of the atoms.

    While eliminating the external cooling is nice, the volume, cost and power consumption of the many lasers used to control the positions of the atoms and to interrogate their states are very high, so I am not convinced that this is indeed an improvement over superconducting qubits.

    Moreover, such lattices of atoms that float in a vacuum chamber while held in position only by laser beams have only a short lifetime until an instability destroys the lattice and the device must be reset. So any quantum computation must not take too much time, or it will fail.

    This technology is the same that has been used for decades for one of the kinds of optical atomic clocks. It has been repurposed now for quantum computation. (The other kinds of atomic clocks use trapped ions instead of lattices of neutral atoms, which are much more stable but have lower signal to noise ratio, or, for lower performance, absorption cells with metallic vapor or molecular gases.)

    Free article: https://arxiv.org/abs/2403.12021

    Another team reports a 3000 qubit lattice, but with a longer lifetime: https://arxiv.org/abs/2506.20660

  • skybrian 3 hours ago
    Though it doesn’t do anything useful yet, this seems really impressive.

    Does anyone have recommended reading to get a better sense of future prospects for quantum computing? My assumption has always been that practical applications are at least ten years away, but maybe not.

    Also, the applications of quantum computing that I’ve heard of are offensive attacks, like breaking encryption or stealing bitcoins. Are there pro-social uses?