Seminar: Kishore Thapliyal
Friday 26th of May Kishore Thapliyal, from Palacky University, Olomouc, Czecch Republic, will visit the Quantum Hub and tell us about his work on secure quantum computation.
Title and abstract:
Experimental generation of engineered multi-mode quantum states to use in secure quantum computation
The idea of secure multiparty computation will be briefly reviewed. With the help of an example relevance of a quantum solution for such secure computation tasks in socioeconomic problems will be mentioned. Such relevant socioeconomic problems could be auction, voting, private comparison, etc. Quantum solutions for one such problem, anonymous veto, will be proposed with focus on the requirements of the desirable protocol. The solution uses multiparty densecoding which requires entanglement to be shared among the voters. A multiparty densecoding based protocol for quantum conference will also be discussed. Generation, transmission, and maintenance of such entangled states is a challenging task. In this context, some non-Gaussian operations are known useful for entanglement distillation. Here, we discuss photon subtraction on both signal and idler beams of a multi-mode twin beam generated experimentally. Joint photon-number distributions of photon-subtracted twin beams are monitored by an iCCD camera. The effect of photon subtraction on average photon numbers, nonclassical and non-Gaussian properties and entanglement of the generated states is studied considering the states obtained by subtracting up to four signal and idler photocounts.
References
[1] S. Mishra, K. Thapliyal, A. Parakh, and A. Pathak, Quantum anonymous veto: A set of new protocols, EPJ Quantum Technology 9, 14 (2022).
[2] K. Thapliyal, J. Peřina Jr., V. Michalek, R. Machulka, and O. Haderka, Experimental characterization of photon-subtracted twin beams, Communicated (2023).