Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Chinese Science Bulletin

NMR experimental implementation of three-parties quantum superdense coding

Daxiu Wei, Xiaodong Yang, J. L. Luo, Xianping Sun, Xizhi Zeng, Maili Liu

Published Jan 1, 2004• 63 citations
Publisher

Abstract

In this study, we report an experiment realization of quantum superdense coding (QSDC) between three parties using nuclear magnetic resonance (NMR). The experimental results have shown that in terms of the QSDC schemes between multiparties proposed by Liu et al. and Crudka et al., three-qubit QSDC can transmit three bits of classical information by sending two qubits only. Our results experimentally show that quantum superdense coding, as one of the quantum information processing protocols, is superior to classical ones.

DOI
10.1007/bf02900957

Related papers

Quantum information processing(QIP) and realization using nuclear magnetic resonance

Da Wei

This paper presents our theoretical and nuclear magnetic resonance(NMR) experimental work on several QIPs including quantum super dense coding(QSDC),quantum algorithms,quantum error correction,and decoherence-free subspace.The main contents are,(1) Using NMR technique,we realize two kinds of QSDC.The experimental results show that QSDC only needs to transfer(N-1) qubits during transmitting N bits classical information;(2) On NMR quantum computers,we realize three kinds of quantum algorithms that include four-qubit summing algorithm,four-qubit Deutsch-like algorithm and seven-qubit Deutsch-Jozsa algorithm;(3) We present a quantum error correction scheme based on quantum cloning.This scheme shows the relationship between quantum cloning and quantum error correction;(4) To avoid decoherence in quantum algorithms,we construct a decoherence-free subspace(DFS) by using multiple quantum coherences.The validity of this DFS is also experimentally verified on our NMR quantum computers.The DFS makes the three unaddressed protons in a CH_3 group distinguished in two-dimensional(2D) NMR.It can protect against more error operators.This idea may provide new insights into extending the number of qubits in the sense that it effectively utilizes the magnetically equivalent nuclei.

Journal of the Graduate School of the Chinese Academy of Sciences•Jan 1, 2007•0 citations

Multiple Round Quantum Dense Coding And Its Implementation Using Nuclear Magnetic Resonance

Jingfu Zhang, Jingyi Xie, Chuan Xi Wang +3 more

A multiple round quantum dense coding (MRQDC) scheme based on the quantum phase estimation algorithm is proposed. Using an $m+1$ qubit system, Bob can transmit $2^{m+1}$ messages to Alice, through manipulating only one qubit and exchanging it between Alice and Bob for $m$ rounds. The information capacity is enhanced to $m+1$ bits. We have implemented the scheme in a three- qubit nuclear magnetic resonance (NMR) quantum computer. The experimental results show a good agreement between theory and experiment.

arXiv:quant-ph/0407104•Jul 14, 2004•0 citations

Experimental implementation of dense coding using nuclear magnetic resonance

Ximing Fang, Xiwen Zhu, Mang Feng +2 more

Quantum dense coding has been demonstrated experimentally in terms of quantum logic gates and circuits in quantum computation and NMR technique. Two bits of information have been transmitted through manipulating one of the maximally entangled two-state quantum pairs, which is completely consistent with the original ideal of the Bennett-Wiesner proposal. Although information transmission happens between spins over interatomic distance, the scheme of entanglement transformation and measurement can be used in other processes of quantum information and quantum computing.

arXiv:quant-ph/9906041•Physical Review A•Jan 13, 2000•124 citations

Exploring the Scalability and Error Tolerance of N-Qubit Superdense Coding

Heinz, Benjamin

Superdense coding is a quantum communication protocol that enables the transmission of more than one classical bit of information per qubit, using entangled states. While superdense coding with 2-qubits is well understood and directly maps to the Bell states, the same cannot be said for higher numbers of qubits. This project aims to develop an algorithm for superdense coding using a larger number of qubits, while analyzing how the capacity for information transmission scales with qubit count. Additionally, we will determine the error thresholds for accurately reconstructing the encoded information and investigate how error scales as the number of qubits increases. Gaining a deeper understanding of superdense coding has significant applications in quantum cryptography, as superdense coding schemes can be used to set up quantum secure direct communication (QSDC) protocols.

•Apr 12, 2025•0 citations

Entanglement witness derived from NMR superdense coding

Robabeh Rahimi, Kazuyuki Takeda, Masanao Ozawa +1 more

It is shown that superdense coding (SDC) experiments by means of nuclear magnetic resonance (NMR) can show non-classical efficiency gain over classical communication only for nuclear spin polarization beyond a certain threshold, and this threshold coincides with that for non-separability of the density matrix. It is also claimed that transfer of two-bit information mediated by a single qubit in the previous NMR SDC experiments with low nuclear spin polarization is not ascribed to the non-classical effect induced by entanglement, but merely to a statistical effect in an ensemble system having a large number of molecules. Towards experimental detection of entanglement, a new class of entanglement witnesses is proposed, which is based on the measurement of nuclear spin magnetizations in the Bell basis and is suitable for actual NMR experiments.

arXiv:quant-ph/0405175•Journal of Physics A Mathematical and General•Feb 15, 2006•14 citations

Information Transmission between Non Direct-coupled Spins in NMR Quantu m Computer

Zeng Xi-zhi

In nuclear magnetic resonance (NMR) system, the interaction s between two arbitrary non direct-coupled spins always become very small along w ith the increasing of their distance. So it is very difficult to realize the inf ormation transmission between two non direct-coupled spins. Fortunately, by int roducing the quantum super dense coding (QSDC) and the spin swap operation, this difficulty can be overcome. In this paper, we analyze the scheme of transmitting information between two non direct-coupled spins. We also demonstrate the scheme on NMR simulation qua ntum computer and Bruker ARX-500 NMR quantum computer.

Yuanzihe wuli pinglun•Jan 1, 2002•0 citations
In this study, we report an experiment realization of quantum superdense coding (QSDC) between three parties using nuclear magnetic resonance (NMR). The experimental results have shown that in terms of the QSDC schemes between multiparties proposed by Liu et al. and Crudka et al., three-qubit QSDC can transmit three bits of classical information by sending two qubits only. Our results experimentally show that quantum superdense coding, as one of the quantum information processing protocols, is superior to classical ones.
This paper presents our theoretical and nuclear magnetic resonance(NMR) experimental work on several QIPs including quantum super dense coding(QSDC),quantum algorithms,quantum error correction,and decoherence-free subspace.The main contents are,(1) Using NMR technique,we realize two kinds of QSDC.The experimental results show that QSDC only needs to transfer(N-1) qubits during transmitting N bits classical information;(2) On NMR quantum computers,we realize three kinds of quantum algorithms that include four-qubit summing algorithm,four-qubit Deutsch-like algorithm and seven-qubit Deutsch-Jozsa algorithm;(3) We present a quantum error correction scheme based on quantum cloning.This scheme shows the relationship between quantum cloning and quantum error correction;(4) To avoid decoherence in quantum algorithms,we construct a decoherence-free subspace(DFS) by using multiple quantum coherences.The validity of this DFS is also experimentally verified on our NMR quantum computers.The DFS makes the three unaddressed protons in a CH_3 group distinguished in two-dimensional(2D) NMR.It can protect against more error operators.This idea may provide new insights into extending the number of qubits in the sense that it effectively utilizes the magnetically equivalent nuclei.
A multiple round quantum dense coding (MRQDC) scheme based on the quantum phase estimation algorithm is proposed. Using an m+1m+1m+1 qubit system, Bob can transmit 2m+12^{m+1}2m+1 messages to Alice, through manipulating only one qubit and exchanging it between Alice and Bob for mmm rounds. The information capacity is enhanced to m+1m+1m+1 bits. We have implemented the scheme in a three- qubit nuclear magnetic resonance (NMR) quantum computer. The experimental results show a good agreement between theory and experiment.
Quantum dense coding has been demonstrated experimentally in terms of quantum logic gates and circuits in quantum computation and NMR technique. Two bits of information have been transmitted through manipulating one of the maximally entangled two-state quantum pairs, which is completely consistent with the original ideal of the Bennett-Wiesner proposal. Although information transmission happens between spins over interatomic distance, the scheme of entanglement transformation and measurement can be used in other processes of quantum information and quantum computing.
Superdense coding is a quantum communication protocol that enables the transmission of more than one classical bit of information per qubit, using entangled states. While superdense coding with 2-qubits is well understood and directly maps to the Bell states, the same cannot be said for higher numbers of qubits. This project aims to develop an algorithm for superdense coding using a larger number of qubits, while analyzing how the capacity for information transmission scales with qubit count. Additionally, we will determine the error thresholds for accurately reconstructing the encoded information and investigate how error scales as the number of qubits increases. Gaining a deeper understanding of superdense coding has significant applications in quantum cryptography, as superdense coding schemes can be used to set up quantum secure direct communication (QSDC) protocols.
It is shown that superdense coding (SDC) experiments by means of nuclear magnetic resonance (NMR) can show non-classical efficiency gain over classical communication only for nuclear spin polarization beyond a certain threshold, and this threshold coincides with that for non-separability of the density matrix. It is also claimed that transfer of two-bit information mediated by a single qubit in the previous NMR SDC experiments with low nuclear spin polarization is not ascribed to the non-classical effect induced by entanglement, but merely to a statistical effect in an ensemble system having a large number of molecules. Towards experimental detection of entanglement, a new class of entanglement witnesses is proposed, which is based on the measurement of nuclear spin magnetizations in the Bell basis and is suitable for actual NMR experiments.
In nuclear magnetic resonance (NMR) system, the interaction s between two arbitrary non direct-coupled spins always become very small along w ith the increasing of their distance. So it is very difficult to realize the inf ormation transmission between two non direct-coupled spins. Fortunately, by int roducing the quantum super dense coding (QSDC) and the spin swap operation, this difficulty can be overcome. In this paper, we analyze the scheme of transmitting information between two non direct-coupled spins. We also demonstrate the scheme on NMR simulation qua ntum computer and Bruker ARX-500 NMR quantum computer.