On Mon, Sep 30, 2019 at 7:10 PM Lawrence Crowell < [email protected]> wrote:
> If they can sustain a qubit for one minute they must have a fairly robust > quantum error correction code. > Not necessarily. Take a look at this article from 2013, it only involved single isolated Qubits not 10 interlocking ones as in the more recent work but "*the coherence time of the qubits was extended to 3 hours at cryogenic temperatures and 39 minutes at room temperature*": Room-Temperature Quantum Bit Storage Exceeding 39 Minutes Using Ionized Donors in Silicon-28 <https://science.sciencemag.org/content/342/6160/830> John K Clark A 10-qubit solid-state spin register with quantum memory up to one minute > C. E. Bradley > <https://arxiv.org/search/quant-ph?searchtype=author&query=Bradley%2C+C+E> > , J. Randall > <https://arxiv.org/search/quant-ph?searchtype=author&query=Randall%2C+J>, M. > H. Abobeih > <https://arxiv.org/search/quant-ph?searchtype=author&query=Abobeih%2C+M+H> > , R. C. Berrevoets > <https://arxiv.org/search/quant-ph?searchtype=author&query=Berrevoets%2C+R+C> > , M. J. Degen > <https://arxiv.org/search/quant-ph?searchtype=author&query=Degen%2C+M+J>, M. > A. Bakker > <https://arxiv.org/search/quant-ph?searchtype=author&query=Bakker%2C+M+A> > , M. Markham > <https://arxiv.org/search/quant-ph?searchtype=author&query=Markham%2C+M>, D. > J. Twitchen > <https://arxiv.org/search/quant-ph?searchtype=author&query=Twitchen%2C+D+J> > , T. H. Taminiau > <https://arxiv.org/search/quant-ph?searchtype=author&query=Taminiau%2C+T+H> > (Submitted on 6 May 2019 (v1 <https://arxiv.org/abs/1905.02094v1>), last > revised 9 May 2019 (this version, v2)) > > Spins associated to single defects in solids provide promising qubits for > quantum information processing and quantum networks. Recent experiments > have demonstrated long coherence times, high-fidelity operations and > long-range entanglement. However, control has so far been limited to a few > qubits, with entangled states of three spins demonstrated. Realizing larger > multi-qubit registers is challenging due to the need for quantum gates that > avoid crosstalk and protect the coherence of the complete register. In this > paper, we present novel decoherence-protected gates that combine dynamical > decoupling of an electron spin with selective phase-controlled driving of > nuclear spins. We use these gates to realize a 10-qubit quantum register > consisting of the electron spin of a nitrogen-vacancy center and 9 nuclear > spins in diamond. We show that the register is fully connected by > generating entanglement between all 45 possible qubit pairs, and realize > genuine multipartite entangled states with up to 7 qubits. Finally, we > investigate the register as a multi-qubit memory. We show coherence times > up to 63(2) seconds - the longest reported for a single solid-state qubit - > and demonstrate that two-qubit entangled states can be stored for over 10 > seconds. Our results enable the control of large quantum registers with > long coherence times and therefore open the door to advanced quantum > algorithms and quantum networks with solid-state spin qubits. > > Subjects: Quantum Physics (quant-ph); Mesoscale and Nanoscale Physics > (cond-mat.mes-hall) > Journal reference: Phys. Rev. X 9, 031045 (2019) > DOI: 10.1103/PhysRevX.9.031045 > <https://arxiv.org/ct?url=https%3A%2F%2Fdx.doi.org%2F10.1103%2FPhysRevX.9.031045&v=785c2928> > Cite as: arXiv:1905.02094 <https://arxiv.org/abs/1905.02094> [quant-ph] > (or arXiv:1905.02094v2 <https://arxiv.org/abs/1905.02094v2> [quant-ph] for > this version) > > -- > You received this message because you are subscribed to the Google Groups > "Everything List" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/everything-list/700eb606-a3dd-484f-98cc-372f27a6f0bf%40googlegroups.com > <https://groups.google.com/d/msgid/everything-list/700eb606-a3dd-484f-98cc-372f27a6f0bf%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/CAJPayv3PagJcbMYPVT-44QKFPgpXybozZ-O6Zwfq5Rx3VLN9vw%40mail.gmail.com.
