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Related papers: Magic and communication complexity

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Quantum communications promises reliable transmission of quantum information, efficient distribution of entanglement and generation of completely secure keys. For all these tasks, we need to determine the optimal point-to-point rates that…

Quantum Physics · Physics 2017-04-27 Stefano Pirandola , Riccardo Laurenza , Carlo Ottaviani , Leonardo Banchi

We present and experimentally demonstrate a communication protocol that employs shared entanglement to reduce errors when sending a bit over a particular noisy classical channel. Specifically, it is shown that, given a single use of this…

Quantum Physics · Physics 2011-04-01 R. Prevedel , Y. Lu , W. Matthews , R. Kaltenbaek , K. J. Resch

The question of finding a lower bound on the number of Toffoli gates in a classical reversible circuit is addressed. A method based on quantum information concepts is proposed. The method involves solely concepts from quantum information -…

Quantum Physics · Physics 2007-05-23 Sandu Popescu , Berry Groisman , Serge Massar

We prove a lower bound on the communication complexity of computing the $n$-fold xor of an arbitrary function $f$, in terms of the communication complexity and rank of $f$. We prove that $D(f^{\oplus n}) \geq n \cdot…

Computational Complexity · Computer Science 2024-07-03 Siddharth Iyer , Anup Rao

Prior work of Beverland et al. has shown that any exact Clifford+$T$ implementation of the $n$-qubit Toffoli gate must use at least $n$ $T$ gates. Here we show how to get away with exponentially fewer $T$ gates, at the cost of incurring a…

Quantum Physics · Physics 2025-10-09 David Gosset , Robin Kothari , Chenyi Zhang

Magic is the resource that quantifies the amount of beyond-Clifford operations necessary for universal quantum computing. It bounds the cost of classically simulating quantum systems via stabilizer circuits central to quantum error…

Quantum Physics · Physics 2025-03-20 Xhek Turkeshi , Emanuele Tirrito , Piotr Sierant

Research on quantum computing has recently gained significant momentum since first physical devices became available. Many quantum algorithms make use of so-called oracles that implement Boolean functions and are queried with highly…

Quantum Physics · Physics 2019-06-07 Alwin Zulehner , Philipp Niemann , Rolf Drechsler , Robert Wille

We introduce the magic hierarchy, a quantum circuit model that alternates between arbitrary-sized Clifford circuits and constant-depth circuits with two-qubit gates ($\textsf{QNC}^0$). This model unifies existing circuit models, such as…

Quantum Physics · Physics 2025-08-29 Natalie Parham

Communication scenarios between two parties can be implemented by first encoding messages into some states of a physical system which acts as the physical medium of the communication and then decoding the messages by measuring the state of…

Quantum Physics · Physics 2024-04-23 Teiko Heinosaari , Oskari Kerppo , Leevi Leppäjärvi , Martin Plávala

While exponential separations are known between quantum and randomized communication complexity for partial functions (Raz, STOC 1999), the best known separation between these measures for a total function is quadratic, witnessed by the…

Quantum methods allow to reduce communication complexity of some computational tasks, with several separated partners, beyond classical constraints. Nevertheless, experimental demonstrations of this fact are thus far limited to some…

Quantum Physics · Physics 2014-06-18 S. Muhammad , A. Tavakoli , M. Kurant , M. Pawlowski , M. Zukowski , M. Bourennane

In a recent work (Ghazi et al., SODA 2016), the authors with Komargodski and Kothari initiated the study of communication with contextual uncertainty, a setup aiming to understand how efficient communication is possible when the…

Information Theory · Computer Science 2017-05-03 Badih Ghazi , Madhu Sudan

The communication cost of algorithms (also known as I/O-complexity) is shown to be closely related to the expansion properties of the corresponding computation graphs. We demonstrate this on Strassen's and other fast matrix multiplication…

Data Structures and Algorithms · Computer Science 2011-09-12 Grey Ballard , James Demmel , Olga Holtz , Oded Schwartz

We prove that, to compute a Boolean function $f$ on $N$ variables with error probability $\epsilon$, any quantum black-box algorithm has to query at least $\frac{1 - 2\sqrt{\epsilon}}{2} \rho_f N = \frac{1 - 2\sqrt{\epsilon}}{2} \bar{S}_f$…

Quantum Physics · Physics 2007-05-23 Yaoyun Shi

We show a lower bound on expected communication cost of interactive entanglement assisted quantum state redistribution protocols and a slightly better lower bound for its special case, quantum state transfer. Our bound implies that the…

Quantum Physics · Physics 2015-10-06 Anurag Anshu

We show a partial Boolean function $f$ together with an input $x\in f^{-1}\left(*\right)$ such that both $C_{\bar{0}}\left(f,x\right)$ and $C_{\bar{1}}\left(f,x\right)$ are at least $C\left(f\right)^{2-o\left(1\right)}$. Due to recent…

Computational Complexity · Computer Science 2021-03-10 Kaspars Balodis

In quantum mechanics, a fundamental law prevents quantum communications to simultaneously achieve high rates and long distances. This limitation is well known for point-to-point protocols, where two parties are directly connected by a…

Quantum Physics · Physics 2020-04-06 Stefano Pirandola

We describe a general quantum receiver protocol that maps laser-light-modulated classical communications signals into quantum processors for decoding with quantum logic. The quantum logic enables joint quantum measurements over a codeword…

Quantum Physics · Physics 2026-03-16 Kelly Werker Smith , Don Boroson , Saikat Guha , Johannes Borregaard

A fundamental limitation of quantum communication is that a single qubit can carry at most 1 bit of classical information. For an important class of quantum communication channels, known as entanglement-breaking, this limitation holds even…

Quantum Physics · Physics 2025-02-14 Giulio Chiribella , Saptarshi Roy , Tamal Guha , Sutapa Saha

In this paper we study quantum nondeterminism in multiparty communication. There are three (possibly) different types of nondeterminism in quantum computation: i) strong, ii) weak with classical proofs, and iii) weak with quantum proofs.…

Computational Complexity · Computer Science 2013-08-13 Marcos Villagra , Masaki Nakanishi , Shigeru Yamashita , Yasuhiko Nakashima