Nonlinear transformation of complex amplitudes via quantum singular value transformation

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Guo, Naixu, Mitarai, Kosuke, Fujii, Keisuke
Natura: Preprint
Pubblicazione: 2021
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866917668030775296
author Guo, Naixu
Mitarai, Kosuke
Fujii, Keisuke
author_facet Guo, Naixu
Mitarai, Kosuke
Fujii, Keisuke
contents Due to the linearity of quantum operations, it is not straightforward to implement nonlinear transformations on a quantum computer, making some practical tasks like a neural network hard to be achieved. In this work, we define a task called nonlinear transformation of complex amplitudes and provide an algorithm to achieve this task. Specifically, we construct a block-encoding of complex amplitudes from a state preparation unitary. This allows us to transform the complex amplitudes by using quantum singular value transformation. We evaluate the required overhead in terms of input dimension and precision, which reveals that the algorithm depends on the roughly square root of input dimension and achieves an exponential speedup on precision compared with previous work. We also discuss its possible applications to quantum machine learning, where complex amplitudes encoding classical or quantum data are processed by the proposed method. This paper provides a promising way to introduce highly complex nonlinearity of the quantum states, which is essentially missing in quantum mechanics.
format Preprint
id arxiv_https___arxiv_org_abs_2107_10764
institution arXiv
publishDate 2021
record_format arxiv
spellingShingle Nonlinear transformation of complex amplitudes via quantum singular value transformation
Guo, Naixu
Mitarai, Kosuke
Fujii, Keisuke
Quantum Physics
Data Structures and Algorithms
Due to the linearity of quantum operations, it is not straightforward to implement nonlinear transformations on a quantum computer, making some practical tasks like a neural network hard to be achieved. In this work, we define a task called nonlinear transformation of complex amplitudes and provide an algorithm to achieve this task. Specifically, we construct a block-encoding of complex amplitudes from a state preparation unitary. This allows us to transform the complex amplitudes by using quantum singular value transformation. We evaluate the required overhead in terms of input dimension and precision, which reveals that the algorithm depends on the roughly square root of input dimension and achieves an exponential speedup on precision compared with previous work. We also discuss its possible applications to quantum machine learning, where complex amplitudes encoding classical or quantum data are processed by the proposed method. This paper provides a promising way to introduce highly complex nonlinearity of the quantum states, which is essentially missing in quantum mechanics.
title Nonlinear transformation of complex amplitudes via quantum singular value transformation
topic Quantum Physics
Data Structures and Algorithms
url https://arxiv.org/abs/2107.10764