Cornelius Hempel

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Cornelius Hempel

Cornelius Hempel

@CHQuant

Building a #quantumcomputer testbed at the @ETH_en-@psich_en Quantum Computing Hub | former @ARC_EQUS @Sydney_Uni and @iqoqi @uniinnsbruck

Switzerland เข้าร่วม Aralık 2017
258 กำลังติดตาม979 ผู้ติดตาม
Cornelius Hempel รีทวีตแล้ว
Kenneth Brown
Kenneth Brown@kenbrownquantum·
A thread about conical intersections. When the pandemic started, all the experimentalists, including Jacob Whitlow and Zhubing Jia, were kicked out of lab. I suggested that Jacob and Gloria think about whether or not we could simulate conical intersections with our ion traps.
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Cornelius Hempel
Cornelius Hempel@CHQuant·
It’s been a few year since @IvanKassal and I talked about CIs over lunch and I moved to🇨🇭in the meantime. Now, with the hard work of many talented people, this analog QSim finally turned into reality. I am very proud of the teams @Sydney_Science @ARC_EQUS that made it happen!
Ivan Kassal@IvanKassal

📰Paper alert! "Direct observation of geometric phase in dynamics around a conical intersection" Geometric phases are counterintuitive and affect the outcomes of chemical reactions, but have never been directly observed... until now! Preprint: arxiv.org/abs/2211.07320

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Cornelius Hempel
Cornelius Hempel@CHQuant·
@Ion_busters We have actually used RAP to measure the Fock state population in this way a couple of years ago when demonstrating EIT cooling with 18 ions. The technique was very well hidden in our paper, however: arxiv.org/abs/1603.05568
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Ion busters
Ion busters@Ion_busters·
Whilst ion traps can operate at high temperature, the ions themselves often need to be cooled to the ground state. Typically people use sideband cooling to do so. But what if you can't? Lee et al demonstrate a novel method using measurement to do so. arxiv.org/abs/2208.05332
Ion busters tweet mediaIon busters tweet media
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Cornelius Hempel
Cornelius Hempel@CHQuant·
@Tonyransford @DavidHa03746758 Again, our focus is on ultimate detection fidelity, if you managed to shelve to the F state. We suggest a few ways to do that as the D state decay you mention is limiting, otherwise.
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Tony
Tony@Tonyransford·
@DavidHa03746758 .@CHQuant that is an impressive paper but I think you would agree that is not SPAM for the high fidelity (1e-6) result but is instead measuring a mixed state. In fact that technique is not possible to do better than a fewe-4 due to the D5/2 to D3/2 decay which seems to be ignored
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Cornelius Hempel
Cornelius Hempel@CHQuant·
@Tonyransford @DavidHa03746758 Point taken, we did not measure SPAM in the way you did but just how well we could separate the two populations - using the same technique you also pursued, we just did not think that 200 ms of shelving per shot is reasonable for any practical use…
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Tony
Tony@Tonyransford·
@DavidHa03746758 I think even in the paper there is no claim of "SPAM" just "detect fidelity" you must be able to single shot prepare two pure states and discriminate from them or it is not much different than measuring a classical coin
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Cornelius Hempel รีทวีตแล้ว
Natascha Hedrich
Natascha Hedrich@NataschaHedrich·
Still looking for something to do today? Look no further! Come by #SwissScienceCenterTechnorama, and see single atoms ⚛️ Also meet our team and ask all of your burning questions. Thanks to @ETH_physics, @snf_ch Agora, and Technorama for making this possible!
Natascha Hedrich tweet media
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Cornelius Hempel
Cornelius Hempel@CHQuant·
It’s worth to re-share this link to help judge how much trust one should put into a rapid antigen test: 122 test kits evaluated by @PEI_Germany Take away: if you have low viral load (e.g. thanks to a booster shot) most kits see nothing! pei.de/SharedDocs/Dow…
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Tilman Esslinger
Tilman Esslinger@TilmanEsslinger·
Last Sunday, after the volcano eruption our environmental control system ENVICO recorded a rather sudden increase in pressure in all our quantum gas labs @ETH_physics
Tilman Esslinger tweet media
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