## Contact

## Bio

### Previous work

Mattia Walschaers got his PhD from the universities of Freiburg (Germany) and Leuven (Belgium) for a cotutelle project, supervised by *Andreas Buchleitner* and *Mark Fannes*. His work initially focused on the role of **quantum effects in photosynthesis**, where he developed analytically solvable toy models to better understand the role of disorder in coherent transport of photosynthetic excitons. Later on, his interest shifted to many-particle systems. First he tried to understand the highest possible current that can flow through **many-fermion systems in a non-equilibrium steady state**. Then the attention shifted to dynamical features of many-particle systems on transient time scales. In particular, Mattia spent a big part of the final years of his PhD project working on **many-particle interference** a phenomenon which induced by indistinguishability of quantum particles. This ultimately led to the development of an experimentally implementable **statistical benchmark for boson sampling.**The resulting dissertation was published as a book in the

*Springer Theses*series, and it was also one of the four nominees for the

*SAMOP dissertation prize*of the German Physical Society.

Since September 2016, Mattia is a post-doctoral researcher in multimode quantum optics group of the *Laboratoire Kastler Brossel*, where his research interests shifted to **continuous-variable quantum optics and quantum information**. With specific interest for highly multimode systems, he mixes standard approaches in the field with **tools from statistical physics**. At the moment, most of his attention is devoted to understanding **experimentally feasible non-Gaussian states **in these systems. As such, he used techniques based on multimode correlation functions to develop a general framework to study **multimode photon addition and subtraction**. Between May 2018 and October 2019, Mattia was funded by a research fellowship from the *German Research Foundation* (DFG) to extend his stay at the LKB and further explore these topics.

### Current work

In April 2019, Mattia was recruited by the CNRS and in October 2019 he started a permanent research position at the LKB. His research builds up on his post-doc work in the multimode quantum optics group, where he now explores various aspects of continuous variable quantum physics. Among current research interests: **multimode non-Gaussian quantum states, quantum correlations in CV systems, quantum batteries, complex quantum networks, and applications of machine learning in quantum experiments**

## Selected Publications

- M. Walschaers, S. Sarkar, V. Parigi, and N. Treps,
*Tailoring Non-Gaussian Continuous-Variable Graph States*, Phys. Rev. Lett.**121**, 220501 (2018). - M. Walschaers, C. Fabre, V. Parigi, and N. Treps,
*Entanglement and Wigner function negativity of multimode non-Gaussian states*, Phys. Rev. Lett.**119**, 183601 (2017). - M. Walschaers, A. Buchleitner, and M. Fannes,
*On optimal currents of indistinguishable particles,*New J. Phys.**19**, 023025 (2017). - M. Walschaers, J. Kuipers, J.-D. Urbina, K. Mayer, M. C. Tichy, K. Richter, and A. Buchleitner,
*Statistical Benchmark for BosonSampling*, New J. Phys.**18**, 032001 (2016). - M. Walschaers, J. Fernandez-de-Cossio Diaz, R. Mulet, and A. Buchleitner,
*Optimally Designed Quantum Transport across Disordered Networks,*Phys. Rev. Lett.**111**, 180601 (2013).

## Full Bibliography

- Y.-S. Ra, A. Dufour, M. Walschaers, C. Jacquard, T. Michel, C. Fabre, N. Treps,
Nat. Phys. (2019)*Non-Gaussian quantum states of a multimode light field,* - M. Walschaers, Y.-S. Ra, N. Treps,
*Mode-Dependent Loss Model for Multimode Photon-Subtracted States,*Phys. Rev. A**100**, 023828 (2019). - D. S. Phillips, M. Walschaers, J. J. Renema, I. A. Walmsley, N. Treps, J. Sperling,
*Benchmarking of Gaussian boson sampling using two-point correlators*, Phys. Rev. A**99**, 023836 (2019).

##### Research articles

- T. Giordani, F. Flamini, M. Pompili, N. Viggianiello, N. Spagnolo, A. Crespi, R. Osellame, N. Wiebe, M. Walschaers, A. Buchleitner, and F. Sciarrino,
*Experimental statistical signature of many-body quantum interference*, Nat. Photonics**12**, 173-178 (2018). - C. Dittel, G. Dufour, M. Walschaers, G. Weihs, A. Buchleitner, and R. Keil,
*Totally destructive many-particle interference*, Phys. Rev. Lett.**120**, 240404 (2018). - C. Dittel, G. Dufour, M. Walschaers, G. Weihs, A. Buchleitner, and R. Keil,
*Totally destructive interference for permutation-symmetric many-particle states*, Phys. Rev. A**97**, 062116 (2018). - V. N. Shatokhin, M. Walschaers, F. Schlawin, and A. Buchleitner,
*Coherence turned on by incoherent light*, New J. Phys.**20**, 113040 (2018). - M. Walschaers, S. Sarkar, V. Parigi, and N. Treps,
*Tailoring Non-Gaussian Continuous-Variable Graph States*, Phys. Rev. Lett.**121**, 220501 (2018).

##### Books

##### Research articles

- M. Walschaers, A. Buchleitner, and M. Fannes,
*On optimal currents of indistinguishable particles*, New J. Phys.**19**, 023025 (2017). - M. Walschaers, R. Mulet, and A. Buchleitner,
*Scattering Theory of Efficient Quantum Transport across Finite Networks*, J. Phys. B: At. Mol. Opt. Phys.**50**, 224003 (2017). - M. Walschaers, C. Fabre, V. Parigi, and N. Treps,
*Entanglement and Wigner function negativity of multimode non-Gaussian states*, Phys. Rev. Lett.**119**, 183601 (2017). - M. Walschaers, C. Fabre, V. Parigi, and N. Treps,
*Statistical signatures of multimode single-photon added and subtracted states of light*, Phys. Rev. A**96**, 053835 (2017).

##### Research articles

- M. Walschaers, J. Kuipers, J.-D. Urbina, K. Mayer, M. C. Tichy, K. Richter, and A. Buchleitner,
*Statistical Benchmark for BosonSampling*, New J. Phys.**18**, 032001 (2016).

*This article was featured in an associated perspective.* - M. Walschaers, J. Kuipers, and A. Buchleitner,
*From Many-Particle Interference to Correlation Spectroscopy*, Phys. Rev. A**94**(R), 020104 (2016).

##### Review articles

- M. Walschaers, F. Schlawin, T. Wellens, and A. Buchleitner,
*Quantum Transport on Disordered and Noisy Networks: An Interplay of Structural Complexity and Uncertainty*, Annu. Rev. Condens. Matter Phys.**7**, 223 { 248 (2016).

##### Research articles

- T. Zech, M. Walschaers, T. Scholak, R. Mulet, T. Wellens, and A. Buchleitner,
*Quantum transport in biological functional units: Noise, disorder, structure*, Fluct. Noise Lett.**12**, 1340007 (2013). - M. Walschaers, J. Fernandez-de-Cossio Diaz, R. Mulet, and A. Buchleitner,
*Optimally Designed Quantum Transport across Disordered Networks*, Phys. Rev. Lett.**111**, 180601 (2013). - M. Walschaers, R. Mulet, T. Wellens, and A. Buchleitner,
*Statistical theory of designed quantum transport across disordered networks*, Phys. Rev. E**91**, 042137 (2015).

### Research articles

- D. Barral, N. Belabas, K. Bencheikh, J. A. Levenson, M. Walschaers, V. Parigi, N. Treps,
*A versatile entanglement synthesizer in the spatial domain, arXiv:1912.11154* - M. Walschaers and N. Treps,
*Remote generation of Wigner-negativity through Einstein-Podolsky-Rosen steering, arXiv:1912.02778* - F. Flamini, M. Walschaers, N. Spagnolo, N. Wiebe, A. Buchleitner, F. Sciarrino,
*Requirements for the validation of a quantum advantage in Boson Sampling,**arXiv:1904.12318*

### Reviews

- M. Walschaers,
*Signature of Many-Particle Interference*,*arXiv:1908.08370*