Work extraction from unknown quantum sources

Work extraction from unknown quantum sources

Date: 2023-04-18
Time: 11:15
Location: ICTQT room 319
ICTQT Seminar
Speaker: Dominik Šafránek (Institute for Basic Science, South Korea) Abstract I will introduce a protocol which allows to unitarily extract work out of sources of quantum states characterized only by a single type of coarse measurement. This defines a new notion of extractable work, which we call observational ergotropy, because it is directly related to observational […]

Wave and particle realism in quantum delayed-choice experiments

Date: 2023-03-23
Time: 14:00
Location: ICTQT room 45
ICTQT Seminar
Speaker: Pedro Dieguez (ICTQT) Abstract Wheeler’s delayed-choice experiment, a scenario wherein a classical apparatus, typically an interferometer, is settled only after the quantum system has entered it, has corroborated the complementarity principle. However, the quantum version of Wheeler's delayed-choice experiment has challenged the robustness of this principle. Based on the visibility at the output of […]

Generalizing Choi map in M_3 beyond circulant scenario

Date: 2023-03-08
Time: 14:00
Location: room 319 ICTQT
ICTQT Seminar
Speaker: Giovanni Scala (ICTQT, UG) Abstract We introduce a family of positive linear maps in the algebra of 3 x3 complex matrices, which generalizes the seminal positive non-decomposable map originally proposed by Choi. Necessary and sufficient conditions for decomposability are derived and demonstrated. The proposed maps offer a new method for the analysis of bound entangled […]

Quantum transfer of interacting and entangled qubits

Date: 2023-02-15
Time: 14:00
Location: ICTQT room 319
ICTQT Seminar
Speaker: Satoshi Yoshida (University of Tokyo) Abstract In this work, we report a deterministic and exact algorithm to reverse any unknown qubit-encoding isometry operation. We present the semidefinite programming (SDP) to search the Choi matrix representing a quantum circuit reversing any unitary operation. We derive a quantum circuit transforming four calls of any qubit-unitary operation into […]

Quantum transfer of interacting and entangled qubits

Date: 2023-01-11
Time: 12:00
Location: ICTQT room 319
ICTQT Seminar
Speaker: M.Hopjan (J. Stefan Institute, Ljubljana) Abstract Recently it was shown, in the three-dimensional Anderson model [1] and the avalanche model of ergodicity breaking transitions [2], that the spectral form factor and the Thouless time extracted from the spectral form factor are scale invariant quantities at eigenstate transition. Thus they represent useful measures for characterisation […]

How to check universality of quantum gates?

Date: 2022-12-19
Time: 14:15
Location: Quantum Chaos and Quantum Information (Jagiellonian University)
seminar
Speaker: Adam Sawicki (CFT PAN, Warsaw) Abstract Universal quantum gates play a central role in quantum computing. It is well known that in order to construct a universal set of gates for many qudits it is enough to take a universal set for one qudit and extend it by a two-qudit entangling gate. On the […]

Device-independent extraction of min-entropy sources against quantum adversaries using few devices

Date: 2022-12-22
Time: 14:00
Location: ICTQT, room 319
seminar
Speaker: Ravishankar Ramanathan (Hong Kong) Abstract Abstract: It is well known that classical tools do not allow the extraction of randomness from a single random source. On the other hand, quantum theory allows for such extraction even within the device-independent framework. While practically feasible protocols have been proposed for randomness sources that possess a specific […]

General guarantees for randomized benchmarking with random quantum circuits

Date: 2022-12-14
Time: 14:30
Location: Quantum Information and Quantum Computing Working Group
seminar
Speaker: Ingo Roth (Quantum research centre, Technology Innovation Institute, Abu Dhabi, UAE) Abstract Randomized benchmarking protocols have become the prominent tool for assessing the quality of gates on digital quantum computing platforms. In `classical’ variants of randomized benchmarking multi-qubit gates are drawn uniformly from a finite group. The functioning of such schemes can be rigorous […]
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