Phase-Conjugated Inputs Quantum Cloning Machines

Abstract

A quantum cloning machine is introduced that yields $M$ identical optimal clones from $N$ replicas of a coherent state and $N^{\prime }$ replicas of its phase conjugate. It also optimally produces $M^{\prime }=M+N^{\prime }-N$ phase-conjugated clones at no cost. For well chosen input asymmetries $N^{\prime }/(N+N^{\prime })$, this machine is shown to provide better cloning fidelities than the standard $(N+N^{\prime })\to M$ cloner. The special cases of the optimal balanced cloner ($N=N^{\prime }$) and the optimal measurement ($M=\infty$) are investigated.

4 pages (RevTex), 2 figures

References in corpus (3)

• Optimal cloning of coherent states with a linear amplifier and beam splitters
• Optical implementation of continuous-variable quantum cloning machines
• Phase Conjugation of Continuous Quantum Variables

Cited by in corpus (19)

• Gaussian Quantum Information
• Quantum Cloning Machines and the Applications
• Experimental Demonstration of Continuous Variable Cloning with Phase-Conjugate Inputs
• Imaginarity-free quantum multiparameter estimation
• Quantum cloning of orthogonal qubits
• Continuous-Variable Telecloning with Phase-Conjugate Inputs
• Extremal quantum cloning machines
• Continuous-Variable Quantum Cloning of Coherent states with Phase-Conjugate Input Modes Using Linear Optics
• Broadcasting of continuous variable entanglement
• Phase-covariant cloning of coherent states
• Superbroadcasting of continuous variables mixed states
• Optimal copying of entangled two-qubit states
• Cloning and Optimal Gaussian individual attacks for continuous-variable quantum key distribution using coherent states and reverse reconciliation
• Reversibility of continuous-variable quantum cloning
• Quantum uniqueness
• Geometrical Conditions for CPTP Maps and their Application to a Quantum Repeater and a State-dependent Quantum Cloning Machine
• Superbroadcasting of conjugate quantum variables
• State estimation from pair of conjugate qudits
• Strongly non-quantitative classical information in quantum carriers