相关论文: Defending Continuous Variable Teleportation: Why a…

It has been argued [T. Rudolph and B.C. Sanders, Phys. Rev. Lett. {\bf 87}, 077903 (2001)] that continuous-variable quantum teleportation at optical frequencies has not been achieved because the source used (a laser) was not `truly…

It has been argued [T. Rudolph and B.C. Sanders, Phys. Rev. Lett. 87, 077903 (2001)] that continuous-variable quantum teleportation at optical frequencies has not been achieved because the source used (a laser) was not `truly coherent'.…

We show that the sender (Alice) and the receiver (Bob) each require coherent devices in order to achieve unconditional continuous variable quantum teleportation (CVQT), and this requirement cannot be achieved with conventional laser…

I argue that the objections by Rudolph and Sanders \cite{RS} to performing continuous variable quantum teleportation experiments using lasers, as well as the various rebuttals to their paper, are based on a misunderstanding of the Partition…

We give a quantum information-theoretic description of an ideal propagating CW laser field and reinterpret typical quantum-optical experiments in light of this. In particular we show that contrary to recent claims [T. Rudolph and B. C.…

Optical implementations of quantum communication protocols typically involve laser fields. However, the standard description of the quantum state of a laser field is surprisingly insufficient to understand the quantum nature of such…

The argument of Rudolph and Sanders, while technically correct, raises conceptual problems. In particular, if carried to its logical conclusion, it would disallow the use in our theories of any time $t$ with implied resolution beyond that…

We argue that (first-order) coherence is a relative, and not an absolute, property. It is shown how feedforward or feedback can be employed to make two (or more) lasers relatively coherent. We also show that after the relative coherence is…

Light's intrinsic carrier frequency of hundreds of terahertz theoretically enables information processing at terahertz clock rates. In optical quantum computing, continuous-variable quantum teleportation is the fundamental building block…

We give a description of balanced homodyne detection (BHD) using a conventional laser as a local oscillator (LO), where the laser field outside the cavity is a mixed state whose phase is completely unknown. Our description is based on the…

It has recently been argued that the inability to measure the absolute phase of an electromagnetic field prohibits the representation of a laser's output as a quantum optical coherent state. This argument has generally been considered…

Lasers serve as the fundamental workhorses of photonic quantum technologies, with perfectly coherent light fields being essential for many protocols that generate nonclassical light, implement coherent control schemes, and initialize…

To quantify quantum optical coherence requires both the particle- and wave-natures of light. For an ideal laser beam [1,2,3], it can be thought of roughly as the number of photons emitted consecutively into the beam with the same phase.…

We clarify the controversy over the coherent-state (CS) versus the number-state (NS) pictures in quantum optics. The NS picture is equivalent to the CS picture, as long as the phases $\phi$ in the laser fields are randomly distributed, as…

We show that a quantum clock cannot be teleported without prior synchronization between sender and receiver: every protocol using a finite amount of entanglement and an arbitrary number of rounds of classical communication will necessarily…

We give a description of balanced homodyne detection (BHD) using a conventional laser as a local oscillator (LO), where the laser field outside the cavity is a mixed state whose phase is completely unknown. Our description is based on the…

Coherent light sources, such as free electron lasers, provide bright beams for biology, chemistry, physics, and advanced technological applications. Increasing the brightness of these sources requires progressively larger devices, with the…

Quantum information technology is set to transform critical network security using quantum cryptography, and complex scientific and engineering simulations with quantum computing. Quantum computer nodes may be based on a variety of systems,…

Recent works [Y.D. Chong {\it et al.}, Phys. Rev. Lett. {\bf 105}, 053901 (2010); W. Wan {\it et al.}, Science {\bf 331}, 889 (2011)] have shown that the time-reversed process of lasing at threshold realizes a coherent perfect absorber…

We comment on the theoretical quantum state of a propagating laser field proposed by van Enk and Fuchs [quant-ph/0104036, quant-ph/0111157] and clarify that the multimode description of the propagating laser field does not modify our…