A random matrix model for random approximate t-designs

Date: Wednesday, January 25, 2023
Time: 14:00
Host: ICTQT, room 319
Passcode: 3SM3fW
Speaker: Adam Sawicki (Centre for Theoretical Physics, Polish Academy of Sciences) Abstract For a Haar random set $\mathcal{S}\subset U(d)$ of quantum gates we consider the uniform measure $\nu_\mc{S}$ whose support is given by $\mathcal{S}$. The measure $\nu_\mc{S}$ can be regarded as a $\delta(\nu_\mc{S},t)$-approximate $t$-design, $t\in\mathbb{Z}_+$. We propose a random matrix model that aims to describe […]

Modes and states of light in Gaussian quantum metrology

Date: Tuesday, January 17, 2023
Time: 12:00
Host: UG, Room 411 of New Rektorat (Floor IV)
Speaker: Giacomo Sorelli (Fraunhofer Institute for Optotronics, System Technology and Image Exploitation) Abstract Quantum optical metrology aims to identify ultimate sensitivity bounds for the estimation of parameters encoded into quantum states of the electromagnetic field. In many practical applications, including imaging, microscopy, and remote sensing, the parameter of interest is not only encoded in the […]

Quantum algorithms for search and optimization

Date: Wednesday, January 25, 2023
Time: 11:00
Host: Quantum Computing Colloquium
Passcode: teamnet
Speaker: Andris Ambainis (Center for Quantum Computer Science, Faculty of Computing, University of Latvia) Abstract Quantum algorithms are useful for a variety of problems in search and optimization. This line of work started with Grover's quantum search algorithm which achieved a quadratic speedup over naive exhaustive search but has now developed far beyond it. In […]

Random approximate t-designs

Date: Wednesday, January 18, 2023
Time: 14:30
Host: Quantum Information and Quantum Computing Working Group
Passcode: nisq
Speaker: Adam Sawicki (CTP PAS) Abstract Approximate t-design are ensembles of unitaries that (approximately) recover Haar averages of polynomials in entries of unitaries up to the order t. As such, they find numerous applications throughout quantum information, including randomized benchmarking , efficient estimation of properties of quantum states, decoupling, information transmission and quantum state discrimination. […]

Shallow shadows: expectation estimation using low-depth random Clifford circuits

Date: Wednesday, January 11, 2023
Time: 15:15
Host: Quantum Information and Quantum Computing Working Group
Passcode: nisq
Speaker: Christian Bertoni (Dahlem Center for Complex Quantum Systems, Freie Universitat Berlin, Germany) Abstract Classical shadows have recently emerged as an efficient method to extract expectation values of observables using randomized measurements. In particular, two schemes have been proven to be able to efficiently perform this task for certain classes of observables: random single-qubit Clifford […]

How to check universality of quantum gates?

Date: Monday, December 19, 2022
Time: 14:15
Host: Quantum Chaos and Quantum Information (Jagiellonian University)
Passcode: please contact albertrico23 at gmail.com
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: Thursday, December 22, 2022
Time: 14:00
Host: ICTQT, room 319
Passcode: 3SM3fW
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: Wednesday, December 14, 2022
Time: 14:30
Host: Quantum Information and Quantum Computing Working Group
Passcode: nisq
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 […]