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Related papers: Counterfactual Logic Gates

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A user, Alice, wants to get server Bob to implement a quantum computation for her. However, she wants to leave him blind to what she's doing. What are the minimal communication resources Alice must use in order to achieve…

Quantum Physics · Physics 2025-10-21 Ethan Davies , Alastair Kay

We discuss the implementation of quantum logic in a system of strongly interacting particles. The implementation is qubitless since ``logical qubits'' don't correspond to any physical two-state subsystems. As an illustration, we present the…

Exploiting the effects of quantum interference we put forward an idea of designing three primary logic gates, OR, AND and NOT, using a benzene molecule. Under a specific molecule-lead interface geometry, anti-resonant states appear which…

Mesoscale and Nanoscale Physics · Physics 2018-09-19 Moumita Patra , Santanu K. Maiti

A quantum computer based on an asymmetric coupled dot system has been proposed and shown to operate as the controlled-NOT-gate. The basic idea is (1) the electron is localized in one of the asymmetric coupled dots. (2)The electron transfer…

Quantum Physics · Physics 2008-12-18 Tetsufumi Tanamoto

We demonstrate quantum information can be transferred between two distant participants without any physical particles travelling between them. The key procedure of the counterfactual scheme is to entangle two nonlocal qubits with each other…

Quantum Physics · Physics 2014-04-28 Qi Guo , Liu-Yong Cheng , Li Chen , Hong-Fu Wang , Shou Zhang

Universal logic gates for two quantum bits (qubits) form an essential ingredient of quantum information processing. However, the photons, one of the best candidates for qubits, suffer from the lack of strong nonlinear coupling required for…

Quantum Physics · Physics 2009-11-10 Zhi Zhao , An-Ning Zhang , Yu-Ao Chen , Han Zhang , Jiangfeng Du , Tao Yang , Jian-Wei Pan

Assume that Alice can do only classical probabilistic polynomial-time computing while Bob can do quantum polynomial-time computing. Alice and Bob communicate over only classical channels, and finally Bob gets a state…

Quantum Physics · Physics 2022-11-16 Tomoyuki Morimae , Takashi Yamakawa

Today, almost all information processing is performed using electronic logic circuits operating with up to several gigahertz frequency. All-optical logic, however, that holds the promise to allow up to three orders of magnitude higher speed…

We present a controlled quantum teleportation protocol. In the protocol, quantum information of an unknown state of a 2-level particle is faithfully transmitted from a sender (Alice) to a remote receiver (Bob) via an initially shared…

Quantum Physics · Physics 2009-11-10 T Gao , F L Yan , Z X Wang

Electronic logic gates are the basic building blocks of every computing and micro controlling system. Logic gates are made of switches, such as diodes and transistors. Ion-selective, ionic switches may emulate electronic switches [1-8]. If…

Chemical Physics · Physics 2017-10-11 Haim Grebel

The concrete schemes to realize three types of basic quantum logical gates using linear quadripartite cluster states of optical continuous variables are proposed. The influences of noises and finite squeezing on the computation precision…

Quantum Physics · Physics 2015-05-13 Aihong Tan , Changde Xie , Kunchi Peng

There are no ``unknown quantum states.'' It's a contradiction in terms. Moreover, Alice and Bob are only inanimate objects. They know nothing. What is teleported instantaneously from one system (Alice) to another system (Bob) is the…

Quantum Physics · Physics 2007-05-23 Asher Peres

Recently the authors in [Phys. Rev. Lett. 125, 090401 (2020)] considered the following scenario: Alice and Bob each have half of a pair of entangled qubit state. Bob measures his half and then passes his part to a second Bob who measures…

Quantum Physics · Physics 2021-03-30 Tinggui Zhang , Shao-Ming Fei

In counterfactual quantum key distribution (QKD), two remote parties can securely share random polarization-encoded bits through the blocking rather than the transmission of particles. We propose a semi-counterfactual QKD, i.e., one where…

Quantum Physics · Physics 2013-11-28 Akshata Shenoy H. , R. Srikanth , T. Srinivas

Logical gates studied in quantum computation suggest a natural logical abstraction that gives rise to a new form of unsharp quantum logic. We study the logical connectives corresponding to the following gates: the Toffoli gate, the NOT and…

Quantum Physics · Physics 2007-05-23 G. Cattaneo , M. L. Dalla Chiara , R. Giuntini , R. Leporini

There exist bipartite entangled states whose violations of Clauser-Horne-Shimony-Holt (CHSH) Bell inequality can be observed by a single Alice and arbitrarily many sequential Bobs [Phys. Rev. Lett. 125, 090401 (2020)]. Here we consider its…

Quantum Physics · Physics 2023-11-08 Ya Xi Mao-Sheng Li Libin Fu , Zhu-Jun Zheng

A historical review is given of the emergence of the idea of the quantum logic gate from the theory of reversible Boolean gates. I highlight the quantum XOR or controlled NOT as the fundamental two-bit gate for quantum computation. This…

Quantum Physics · Physics 2009-10-30 David P. DiVincenzo

A classical logic gate connecting input and output light pulses is demonstrated. The gate operation is based on three steps: First, two incoming light pulses are stored in a Bose-Einstein condensate, second, atomic four-wave mixing…

Quantum Physics · Physics 2013-01-03 Christoph Vo , Stefan Riedl , Simon Baur , Gerhard Rempe , Stephan Dürr

The `no communication' theorem prohibits superluminal communication by showing that any measurement by Alice on an entangled system cannot change the reduced density matrix of Bob's state, and hence the expectation value of any measurement…

Quantum Physics · Physics 2022-09-19 Amitava Datta

We consider a distributed quantum hypothesis testing problem with communication constraints, in which the two hypotheses correspond to two different states of a bipartite quantum system, multiple identical copies of which are shared between…

Quantum Physics · Physics 2019-05-03 Hao-Chung Cheng , Nilanjana Datta , Cambyse Rouzé