An efficient verification of quantum circuits under a practical restriction

Author(s):  
Shigeru Yamashita ◽  
Shin-ichi Minato ◽  
D. Michael Miller
2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Ryan S. Bennink

AbstractI present a method for estimating the fidelity F(μ, τ) between a preparable quantum state μ and a classically specified pure target state $$\tau =\left|\tau \right\rangle \left\langle \tau \right|$$ τ = τ τ , using simple quantum circuits and on-the-fly classical calculation (or lookup) of selected amplitudes of $$\left|\tau \right\rangle$$ τ . The method is sample efficient for anticoncentrated states (including many states that are hard to simulate classically), with approximate cost 4ϵ−2(1 − F)dpcoll where ϵ is the desired precision of the estimate, d is the dimension of the Hilbert space, and pcoll is the collision probability of the target distribution. This scaling is exponentially better than that of any method based on classical sampling. I also present a more sophisticated version of the method that uses any efficiently preparable and well-characterized quantum state as an importance sampler to further reduce the number of copies of μ needed. Though some challenges remain, this work takes a significant step toward scalable verification of complex states produced by quantum processors.


Quantum ◽  
2021 ◽  
Vol 5 ◽  
pp. 578
Author(s):  
Ulysse Chabaud ◽  
Frédéric Grosshans ◽  
Elham Kashefi ◽  
Damian Markham

The demonstration of quantum speedup, also known as quantum computational supremacy, that is the ability of quantum computers to outperform dramatically their classical counterparts, is an important milestone in the field of quantum computing. While quantum speedup experiments are gradually escaping the regime of classical simulation, they still lack efficient verification protocols and rely on partial validation. Here we derive an efficient protocol for verifying with single-mode Gaussian measurements the output states of a large class of continuous-variable quantum circuits demonstrating quantum speedup, including Boson Sampling experiments, thus enabling a convincing demonstration of quantum speedup with photonic computing. Beyond the quantum speedup milestone, our results also enable the efficient and reliable certification of a large class of intractable continuous-variable multimode quantum states.


2019 ◽  
Vol 12 (4) ◽  
Author(s):  
Ye-Chao Liu ◽  
Xiao-Dong Yu ◽  
Jiangwei Shang ◽  
Huangjun Zhu ◽  
Xiangdong Zhang

2005 ◽  
Vol 95 (14) ◽  
Author(s):  
V. T. Petrashov ◽  
K. G. Chua ◽  
K. M. Marshall ◽  
R. Sh. Shaikhaidarov ◽  
J. T. Nicholls

2014 ◽  
Vol 16 (9) ◽  
pp. 093026 ◽  
Author(s):  
Mateus Araújo ◽  
Adrien Feix ◽  
Fabio Costa ◽  
Časlav Brukner
Keyword(s):  

2021 ◽  
Author(s):  
Pujitha Perla ◽  
H. Aruni Fonseka ◽  
Patrick Zellekens ◽  
Russell Deacon ◽  
Yisong Han ◽  
...  

Nb/InAs-nanowire Josephson junctions are fabricated in situ by a special shadow evaporation scheme for the superconducting Nb electrode. The junctions are interesting candidates for superconducting quantum circuits requiring large magnetic fields.


2021 ◽  
Vol 5 (POPL) ◽  
pp. 1-29
Author(s):  
Kesha Hietala ◽  
Robert Rand ◽  
Shih-Han Hung ◽  
Xiaodi Wu ◽  
Michael Hicks
Keyword(s):  

2021 ◽  
Vol 103 (5) ◽  
Author(s):  
Oleksandr Kyriienko ◽  
Annie E. Paine ◽  
Vincent E. Elfving

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