PME Special Quantum Seminar: Operational entanglement certification

Entanglement sources that produce many entangled states act as a main component in future quantum networks. Realistic sources are inherently noisy, cannot run for an infinitely long time, and do not necessarily behave in an independent and identically distributed manner. An important question then arises – how can one test, or certify, that a realistic source produces high amounts of entanglement? Crucially, a meaningful and operational solution should allow us to certify the entanglement which is available for further applications after performing the test itself (in contrast to assuming the availability of an additional source which can produce more entangled states, identical to those which were tested).<br /><br />

In the talk, I will start by explaining the difference between “operational entanglement certification” and the current practice of measuring fidelities in experiments. By understanding the different approaches and challenges, we will see an example of how the beautiful combination of physics, computer science, and mathematics emerges in the field of quantum information theory.<br /><br />

Then, going back to the original question of entanglement certification, I will present a protocol that can be executed by interacting classically with uncharacterized measurement devices used to measure the states produced by the source, similarly to Bell test experiments. A successful run of the protocol implies that the remaining quantum state has high amounts of a quantity called “one-shot distillable entanglement”. That is, one can distill many maximally entangled states out of the single remaining state. Importantly, our protocol can tolerate noise and, thus, certify entanglement produced by realistic sources. With the above properties, the protocol acts as the first “operational device-independent entanglement certification protocol” and allows one to test and benchmark uncharacterized entanglement sources, which may be otherwise incomparable.<br /><br />

Hosted By: Hannes Bernien

<a href="https://uchicago.zoom.us/j/93309791829?pwd=cWlLL2RJenY4eCtoU0Y3YnlQUVZk…; Zoom Link </a><br /><br />

Meeting ID: 933 0979 1829<br />
Passcode: 744704