Searcharxiv⌕ Search

arXiv subjects

Zhiheng Lu

Publications and source records attributed to Zhiheng Lu.

12 recordsLinked to original sources
arXiv2005

Simulation of a Heisenberg XY- chain and realization of a perfect state transfer algorithm using liquid nuclear magnetic resonance

The three- spin chain with Heisenberg XY- interaction is simulated in a three- qubit nuclear magnetic resonance (NMR) quantum computer. The evolution caused by the XY- interaction is decomposed into a series of single- spin rotations and the $J$- coupling evolutions between the neighboring spins. The perfect state transfer (PST) algorithm proposed by M. Christandl et al [Phys. Rev. Lett, 92, 187902(2004)] is realized in the XY- chain.

quant-ph↗
arXiv2004

Modularization of multi-qubit controlled phase gate and its NMR implementation

Quantum circuit network is a set of circuits that implements a certain computation task. Being at the center of the quantum circuit network, the multi-qubit controlled phase shift is one of the most important quantum gates. In this paper, we apply the method of modular structuring in classical computer architecture to quantum computer and give a recursive realization of the multi-qubit phase gate. This realization of the controlled phase shift gate is convenient in realizing certain quantum algorithms. We have experimentally implemented this modularized multi-qubit controlled phase gate in a three qubit nuclear magnetic resonance quantum system. The network is demonstrated experimentally using line selective pulses in nuclear magnetic resonance technique. The procedure has the advantage of being simple and easy to implement.

quant-ph↗
arXiv2004

Nuclear Magnetic Resonance Implementation of a Quantum Clock Synchronization Algorithm

The quantum clock synchronization algorithm proposed by I. L. Chuang (Phys. Rev. Lett, 85, 2006(2000)) has been implemented in a three qubit nuclear magnetic resonance quantum system. The effective-pure state is prepared by the spatial averaging approach. The time difference between two separated clocks can be determined by reading out directly through the NMR spectra.

quant-ph↗
arXiv2004

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

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.

quant-ph↗
arXiv2003

NMR implementation of a quantum scheduling algorithm

The improved quantum scheduling algorithm proposed by Grover has been generalized using the generalized quantum search algorithm, in which a unitary operator replaces the Walsh-Hadamard transform, and $π/2$ phase rotations replace the selective inversions, in order to make the quantum scheduling algorithm suitable for more cases. Our scheme is realized on a nuclear magnetic resonance (NMR) quantum computer. Experimental results show a good agreement between theory and experiment.

quant-ph↗
arXiv2002

Implementation of dense coding using the generalized Grover's algorithm

Dense coding has been implemented using the generalized Grover's algorithm and its inverse operation. Exploiting the superpositions of two Einstein-Podolsky-Rosen (EPR) states, messages that are possible to be transmitted increase. Our scheme is demonstrated using nuclear magnetic resonance (NMR). Experimental results show a good agreement between theory and experiment.

quant-ph↗
arXiv2002

Simulating decoherence behavior of a system in entangled state using nuclear magnetic resonance

By choosing H nucleus in Carbon-13 labelled trichloroethylene as one qubit environment, and two C nuclei as a two-qubit system, we have simulated quantum decoherence when the system lies in an entangled state using nuclear magnetic resonance (NMR). Decoupling technique is used to trace over the environment degrees of freedom. Experimental results show agreements with the theoretical predictions. Our experiment scheme can be generalized to the case that environment is composed of multiple qubits.

quant-ph↗
arXiv2002

Experimental study of quantum decoherence using nuclear magnetic resonance

Quantum decoherence has been studied using nuclear magnetic resonance(NMR). By choosing one qubit to simulate environment, we examine the decoherence behavior of two quantum systems: a one qubit system and a two qubit system. The experimental results show agreements with the theoretical predictions. Our experiment schemes can be generalized to the case that the environment is composed of multiple qubits.

quant-ph↗
arXiv2001

Realization of generalized quantum searching using nuclear magnetic resonance

According to the theoretical results, the quantum searching algorithm can be generalized by replacing the Walsh-Hadamard(W-H) transform by almost any quantum mechanical operation. We have implemented the generalized algorithm using nuclear magnetic resonance techniques with a solution of chloroform molecules. Experimental results show the good agreement between theory and experiment.

quant-ph↗