Is there a known measurement-complexity separation for closed-loop control of a drifting observable, or only a constant-factor gain?

Is there a known measurement-complexity separation for closed-loop control of a drifting observable, or only a constant-factor gain? Ask Question Asked today Modified today Viewed 8 times 1 Consider holding a single-qubit observable (say a rotation angle or readout bias) at a setpoint while the device drifts, using closed-loop feedback at one measurement per round, with no model of the device. Gradient-based baselines like SPSA or finite-difference need several measurements to assemble a step. My question is about the fundamental limit, not a specific method: is there any known result establishing a separation in measurement complexity between feedback control and these baselines for this kind of drift-tracking task, or is the best achievable advantage understood to be a constant factor? References to lower bounds or to the relevant control/estimation literature would be ideal. measurementcomplexity-theorynoise Share Improve this question Follow asked 4 hours ago Matt Leibel 111 1 bronze badge New contributor Add a comment Know someone who can answer? Share a link to this question via email, Twitter, or Facebook. Your Answer Sign up or log in Sign up using Google Sign up using Email and Password Post as a guest Name Email Required, but never shown Post Your Answer By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy. Start asking to get answers Find the answer to your question by asking. Ask question Explore related questions measurementcomplexity-theorynoise See similar questions with these tags. The Overflow Blog Code isn’t the only thing causing your production... Paging Charity! How can engineering leaders avoid becoming Bond... Featured on Meta Partnering with Communities to Modernize Policies & Norms Related 4 What does it mean for a result of a measurement to be known/unknown? 3 For CNOT gate with control qubit set to 1, the measured state of the second qubit unexpectedly depends on the measurement 3 Show that for any measurement operator M m 𝑀 𝑚 there exists a unitary U m 𝑈 𝑚 such that M m = U m M † m M m − − − − − − √ 𝑀 𝑚 = 𝑈 𝑚 𝑀 𝑚 † 𝑀 𝑚 7 Do there exist problems known to be computationally intractable for quantum computer, but tractable for classical computer? 2 Show that there are unitaries U m 𝑈 𝑚 such that M m = U m E m − − − √ 𝑀 𝑚 = 𝑈 𝑚 𝐸 𝑚 , for any measurement M m 𝑀 𝑚 and associated POVM E m 𝐸 𝑚 2 Why for every state there is always a measurement that has a deterministic outcome? 3 is there a measurement free decoder for [[5,1,3]] [ [ 5 , 1 , 3 ] ] and [[8,3,3]] [ [ 8 , 3 , 3 ] ] codes 2 How many shots are approximately needed to get a decent signal to noise ratio for a high weight observable at a fixed measurement error rate? Hot Network Questions Why 2N7002 on I2C bus? How can I position text characters side by side based on their bounding boxes in Geometry Nodes? Precision warning while finding roots of equation involving exponential and Bessel function Who Was Higher in 95 AD: The Bishop of Rome or the Apostle John? Why is the `..` entry missing in `dir` output for directories directly under a drive root? more hot questions Question feed By continuing to use this website, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. By exiting this window, default cookies will be accepted. To reject cookies, select an option from below. Customize settings Cookie consent preference center When you visit any of our websites, it may store or retrieve information on your browser, mostly in the form of cookies. This information might be about you, your preferences, or your device and is mostly used to make the site work as you expect it to. The information does not usually directly identify you, but it can give you a more personalized experience. Because we respect your right to privacy, you can choose not to allow some types of cookies. Click on the different category headings to find out more and manage your preferences. Please note, blocking some types of cookies may impact your experience of the site and the services we are able to offer. Cookie policy Accept all cookies Manage consent preferences Strictly Necessary Cookies Always Active These cookies are necessary for the website to function and cannot be switched off in our systems. They are usually only set in response to actions made by you which amount to a request for services, such as setting your privacy preferences, logging in or filling in forms. You can set your browser to block or alert you about these cookies, but some parts of the site will not then work. These cookies do not store any personally identifiable information. Targeting Cookies Targeting Cookies These cookies are used to make advertising messages more relevant to you and may be set through our site by us or by our advertising partners. They may be used to build a profile of your interests and show you relevant advertising on our site or on other sites. They do not store directly personal information, but are based on uniquely identifying your browser and internet device. Performance Cookies Performance Cookies These cookies allow us to count visits and traffic sources so we can measure and improve the performance of our site. They help us to know which pages are the most and least popular and see how visitors move around the site. All information these cookies collect is aggregated and therefore anonymous. If you do not allow these cookies we will not know when you have visited our site, and will not be able to monitor its performance. Functional Cookies Functional Cookies These cookies enable the website to provide enhanced functionality and personalisation. They may be set by us or by third party providers whose services we have added to our pages. If you do not allow these cookies then some or all of these services may not function properly. Cookie List Clear checkbox label label Apply Cancel Consent Leg.Interest checkbox label label checkbox label label checkbox label label Necessary cookies only Confirm my choices