Abstract: TBA

Abstract: Improvements in measurement ability almost always lead to new scientific discoveries. Quantum sensing - the use of quantum systems to make ultra-precise measurements - will be the basis of the next generation of sensing technology. Atom interferometers are quantum sensors based on the coherent control of atomic ensembles. I will discuss some recent breakthroughs in the field, and some applications that this will lead to, such as the ability to monitor the movement of ground-water, and the possibility of resolving the quantum nature of gravity.

Abstract: I introduce a functional able to bound multipartite entanglement, and expressible in terms of one- and two-point correlation functions. I show that it is especially valuable for mixed quantum states, and whenever the experimental measurements and/or numerical simulations of other estimators are difficult or impractical. I discuss the theoretical usability perimeter of the estimator and, by numerical simulations, we provide examples from paradigmatic spin models.

Abstract: Observations on quantum systems can both be used to characterize their physical properties and to detect the perturbation of the same properties, e.g., by external fields or forces.
After a brief review of recent physical implementations of high precision quantum measurements, and their capabilities and limitations, I shall focus the presentation on the case of continuously monitored systems, i.e., the situation where we observe a single quantum system and retrieve a randomly fluctuating time dependent signal. We shall review how such fluctuating signals are optimally analyzed by quantum trajectory theory and how they may, indeed, yield much more information than is available in their integrated values.
Different detection methods yield different sensing capabilities, but it is possible to derive theoretical limits for the maximum sensitivity by all possible quantum detection schemes, and we show that this maximum is sometimes reached by standard measurement schemes in quantum optics.
References:
Søren Gammelmark and Klaus Mølmer, Bayesian parameter inference from continuously monitored quantum systems; Phys. Rev. A 87, 032115 (2013).
Søren Gammelmark and Klaus Mølmer, Fisher Information and the Quantum Cramér-Rao Sensitivity Limit of Continuous Measurements; Phys. Rev. Lett. 112, 170401 (2014).
C. Zhang, K. Mølmer, Estimating a fluctuating magnetic field with a continuously monitored atomic ensemble; Phys. Rev. A 102, 063716 (2020).
Claus Normann Madsen, Lia Valdetaro, Klaus Mølmer, Quantum estimation of a time-dependent perturbation., Phys. Rev. A, 104, 05262 (2021).

Abstract: TBA

Abstract: TBA

Abstract: TBA

Abstract: In this talk, I'll mainly discuss the program logic approach to verification of quantum programs, including quantum Hoare logic, invariant generation and termination analysis for quantum programs. I'll also briefly discuss potential applications of model checking for verification and debugging of quantum programs. Some problems for future research will be proposed at the end of the paper.
Affiliation: Mingsheng Ying, Institute of Software, Chinese Academy of Sciences and Tsinghua University, China