TY  - JOUR
PB  - SciPost Foundation
DO  - 10.21468/SciPostPhys.15.1.007
TI  - Entanglement in the full state vector of boson sampling
PY  - 2023/07/12
UR  - https://www.scipost.org/SciPostPhys.15.1.007
JF  - SciPost Physics
JA  - SciPost Phys.
VL  - 15
IS  - 1
SP  - 007
A1  - Qiao, Yulong
AU  - Huh, Joonsuk
AU  - Grossmann, Frank
AB  - The full state vector of boson sampling is generated by passing $S$ single photons through beam splitters of $M$ modes. We express the initial Fock state in terms of 2$^{S-1}$ generalized coherent states, making possible the exact application of the unitary evolution. Due to the favorable polynomial scaling of numerical effort in $M$, we can investigate Rényi entanglement entropies for moderate particle and huge mode numbers. We find symmetric Page curves with a maximum entropy at equal partition, which is almost independent on Rényi index. Furthermore, the maximum entropy as a function of mode index saturates for $M\geq S^2$ in the collision-free subspace case. The asymptotic value of the entropy increases linearly with $S$. In addition, we show that the build-up of the entanglement leads to a cusp in the asymmetric entanglement curve. Maximum entanglement is reached well before the mode population is distributed over the whole system.
ER  -

@Article{10.21468/SciPostPhys.15.1.007,
	title={{Entanglement in the full state vector of boson sampling}},
	author={Yulong Qiao and Joonsuk Huh and Frank Grossmann},
	journal={SciPost Phys.},
	volume={15},
	pages={007},
	year={2023},
	publisher={SciPost},
	doi={10.21468/SciPostPhys.15.1.007},
	url={https://scipost.org/10.21468/SciPostPhys.15.1.007},
}