Joint Seminar on Quantum Information and Technologies
2012/2013 | 2013/2014 | 2014/2015 | 2015/2016 | 2016/2017 | 2017/2018 | 2018/2019 | 2019/2020 | 2020/2021 | 2021/2022 | 2022/2023 | 2023/2024 | 2024/2025 | YouTube channel
until 2023/2024 Quantum Information Seminar | YouTube channel
2025-06-05 (Thursday)
room 0.06, Pasteura 5 at 11:15 
Lewis Clark (A*STAR, Singapore)Trajectory methods and applications in continuously monitored open quantum systems
2025-05-29 (Thursday)
room 0.06, Pasteura 5 at 11:15
Przemysław Dykowski (Institute of Geodesy and Cartography)Can quantum sensors improve the way we measure Earth’s gravity?
Modern absolute gravity measurements are capable to achieve accuracies at the level of 10-9 g since late 1980s. The instruments most commonly used for gravity measurements operate on mechanical components, i.e. spring tensions or a prism free falling in a vacuum. This creates particular disadvantages in their robustness which potentially can be mitigated with emerging quantum sensors.
In the last two decades quantum sensors are being used for practical gravity measurements and since the last decade a commercial quantum sensor became available commercially to the scientific community, based on atom interferometry, the Absolute Quantum Gravimeter (AQG) manufactured by a French company, Exail. With its compact size, it is a very promising tool for measurements of Earth gravity field. Up to now 19 instruments have been manufactured and distributed worldwide.
Seminar will present aspects of Earth gravity field variations, effects that are taken into account in modern precise gravity measurements, currently available and used instrumentation along with requirements they need to meet as well as the pros and cons of introducing the quantum sensors to the scientific community. Finally results and plans for future research for the AQG-B07 quantum gravimeter (owned by IGiK) will be presented on the national and EU level.
In the last two decades quantum sensors are being used for practical gravity measurements and since the last decade a commercial quantum sensor became available commercially to the scientific community, based on atom interferometry, the Absolute Quantum Gravimeter (AQG) manufactured by a French company, Exail. With its compact size, it is a very promising tool for measurements of Earth gravity field. Up to now 19 instruments have been manufactured and distributed worldwide.
Seminar will present aspects of Earth gravity field variations, effects that are taken into account in modern precise gravity measurements, currently available and used instrumentation along with requirements they need to meet as well as the pros and cons of introducing the quantum sensors to the scientific community. Finally results and plans for future research for the AQG-B07 quantum gravimeter (owned by IGiK) will be presented on the national and EU level.
2025-05-22 (Thursday)
room 0.06, Pasteura 5 at 11:15
Michał Matuszewski (CFT PAN)Quantization of polaritons in confined structures
2025-05-15 (Thursday)
room 0.06, Pasteura 5 at 11:15
Alvaro Alhambra (CSIC Madrid)Modelling quantum thermalization with quantum computers
In quantum computing and simulation, one of our main goals is to efficiently mimic natural physical phenomena in a controlled manner. The process of thermalization is one such crucial task, for which recently there has been relevant progress. In this talk, we will showcase important parts of this progress by introducing a recent dissipative evolution that models thermalization in the many-body setting, and that is efficiently implementable in a quantum computer. We then prove the following facts about this dissipative evolution:
1) It faithfully reproduces the dissipation induced by weak coupling to a bath.2) In the high temperature regime, it very quickly approaches equilibrium.3) In the low temperature regime, it can reproduce arbitrary quantum computations.
Taken together, our results show that quantum dissipative evolutions have the potential to mirror the success of classical Monte Carlo methods.
1) It faithfully reproduces the dissipation induced by weak coupling to a bath.2) In the high temperature regime, it very quickly approaches equilibrium.3) In the low temperature regime, it can reproduce arbitrary quantum computations.
Taken together, our results show that quantum dissipative evolutions have the potential to mirror the success of classical Monte Carlo methods.
2025-04-24 (Thursday)
room 0.06, Pasteura 5 at 11:15
Robert Keil (University of Innsbruck, Austria)Multi-particle interference and photonic quantum interfaces
When two indistinguishable photons impinge on a beam splitter, the particles leave the device together in the same output due to the underlying two-photon interference [1]. This well-known Hong-Ou-Mandel effect is at the basis of photonic quantum information processing and various other applications. For more than two particles, the dynamics gets increasingly complex and a rich variety of interference phenomena can arise. In this talk, I will present our latest experimental results on four-photon interference obtained from spontaneous parametric down-conversion (SPDC). In particular, I will demonstrate how symmetries can affect the ability of interference [2] and how entanglement can lead to a collective four-particle interference, which is completely invisible when smaller subsets of particles are detected [3]. I will also highlight how semiconductor quantum dots can be used as a multi-photon source via active temporal-to-spatial mode demultiplexing [4]. Finally, I will introduce our new project on establishing an interface between SPDC and quantum-dot emitted photons enabled by active spectral-temporal shaping of the photon wavepackets.
[1] Hong, Ou, Mandel, Phys. Rev. Lett. 59, 2044 (1987),
[2] Münzberg et al., PRX Quantum 2, 020326 (2021),
[3] Faleo et al., Sci. Adv. 10, eadp9030 (2024),
[4] Münzberg et al., APL Photonics 7, 070802 (2022)
[1] Hong, Ou, Mandel, Phys. Rev. Lett. 59, 2044 (1987),
[2] Münzberg et al., PRX Quantum 2, 020326 (2021),
[3] Faleo et al., Sci. Adv. 10, eadp9030 (2024),
[4] Münzberg et al., APL Photonics 7, 070802 (2022)
2025-04-10 (Thursday)
room 0.06, Pasteura 5 at 11:15
Marek Szczepańczyk (IFT UW)The quest to detect (exceptional) gravitational-wave sources
Gravitational Wave Astrophysics has already demonstrated its potential to explore the Universe, but we are still at the beginning of this journey. While we regularly observe gravitational waves from compact binaries, we do not know what we may discover next. In my talk, I will give an overview of the field of Gravitational Wave Astrophysics by discussing the gravitational-wave detectors (current status and the future), the sources (standard and exceptional), and the role of model-independent searches in the exploration of the Universe. I will announce an upcoming LIGO-Virgo-KAGRA Symposium in Warsaw on core-collapse supernovae - one of the most interesting sources of gravitational waves. Finally, I will explore interesting venues for the field of gravitational waves.
2025-04-03 (Thursday)
room 0.06, Pasteura 5 at 11:15
Piotr Dulian (IFT UW)QMetro++ - Python package for large scale quantum metrology
2025-03-27 (Thursday)
room 0.06, Pasteura 5 at 11:15
Karolina Słowik (UMK Toruń)On the role of entanglement in two-photon absorption
Optimal excitation of a three-level ladder-type atom by a two-photon light state is analyzed using the Wigner-Weisskopf approximation. The optimal state, enabling perfect excitation with unit probability, is determined by the lifetimes of atomic states, with its entanglement dependent on their ratio. Two distinct interaction regimes are identified, in which entanglement affects the excitation process differently.
The optimal light state is an entangled photon pair. As such states may be challenging to prepare, comparisons are made with experimentally accessible photon pair profiles, whose parameters are optimized to maximize excitation probability. The influence of entanglement on atom excitation and its dependence on atomic properties are discussed.
The optimal light state is an entangled photon pair. As such states may be challenging to prepare, comparisons are made with experimentally accessible photon pair profiles, whose parameters are optimized to maximize excitation probability. The influence of entanglement on atom excitation and its dependence on atomic properties are discussed.
2025-03-20 (Thursday)
room 0.06, Pasteura 5 at 11:15
Sumit Chaudhary (Technical University of Munich)Integration of QKD with classical channels using wavelength division multiplexing
2025-03-13 (Thursday)
room 0.06, Pasteura 5 at 11:15
Sylwia Kolenderska (University of Auckland)