Colloquium: Dr. Vincenzo Tamma, University of Portsmouth
In-Person PHYS 401
Location
Physics : 401
Date & Time
April 20, 2022, 3:30 pm – 4:30 pm
Description
TITLE: Quantum-enhanced metrology based on multi-photon interference
ABSTRACT:
Multiphoton quantum interference underpins fundamental tests of quantum mechanics and quantum technologies, including applications in quantum computing, quantum sensing and quantum communication.
We have shown both theoretically [1] and experimentally [2] how multiphoton interference with states of single or multiple photons enables the characterisation of multiphoton networks and states, the generation of multipartite entanglement, and scales-up boson sampling demonstrations of quantum computational speed-up. This is possible even with non-identical photons by harnessing the full multiphoton quantum information stored in the photonic spectra by measurements able to resolve the photonic inner modes, such as frequency and time.
In this talk, we will focus on how frequency and time resolved measurements allow a precision enhancement in the estimation of the time delay or frequency differences between different photons [3]. Applications range from the characterization of two-dimensional nanomaterials to the analysis of biological samples, including DNA and cell membranes [3].
We will also show how multiphoton interference of squeezed photons with homodyne measurements can be used to achieve Heisenberg limited precision in the estimation of a single unknown parameter or a function of unknown parameters distributed in an arbitrary linear network without the need of adaptive networks or any restrictions in the value of the parameters [4]. Furthermore, we will describe the robustness to losses in the Heisenberg limited estimation of a linear superposition of unknown phases by using a single squeezed vacuum source and an anti-squeezing operation at a single interferometer output [5]. This work can impact the development of new sensors for the estimation of both local and distributed parameters, including temperature, electromagnetic and gravitational fields.
[1] V. Tamma and S. Laibacher, Phys. Rev. A 104, 032204 (2021); S. Laibacher and V. Tamma, Phys. Rev. A 98, 053829 (2018); V. Tamma and S. Laibacher, arXiv:1801.03832; V. Tamma and S. Laibacher, Phys. Rev. Lett. 114, 243601 (2015); S. Laibacher and V. Tamma, Phys. Rev. Lett. 115, 243605 (2015)
[2] X.-J. Wang et al., Phys. Rev. Lett. 121, 080501 (2018); V. V. Orre, et al. Phys. Rev. Lett. 123, 123603 (2019)
[3] D. Triggiani, Giorgos Psaroudis and V. Tamma, arXiv:2112.12102 (2021)
[4] G. Gramegna et al. New J. of Physics 23, 053002 (2021); G. Gramegna et al. Phys. Rev. Research 3, 013152 (2021); D. Triggiani, P. Facchi, and V. Tamma, Phys. Rev. A 104, 062603 (2021); D. Triggiani, P. Facchi, and V. Tamma, Eur. Phys. J. Plus 137:125 (2022)
[5] D. Gatto, P. Facchi and V. Tamma, Phys. Rev. A 105, 012607 (2022); D. Gatto, P. Facchi and V. Tamma, Phys. Rev. Research 1, 032024 (2019)
