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We develop an information theoretic interpretation of the number-phase complementarity in atomic systems, where phase is treated as a continuous positive operator valued measure (POVM). The relevant uncertainty principle is obtained as an…

Quantum Physics · Physics 2015-05-13 R. Srikanth , Subhashish Banerjee

We show that information gain in a qubit measurement is optimal under a Von Neumann measurement. For an initially mixed apparatus kept in touch with a qubit, the conditions for achieving the equality sign of Holevo bound on the information…

Quantum Physics · Physics 2007-05-23 Nima Lashkari

The discrete variables (DV) time-frequency (TF) quantum key distribution (QKD) protocol is a BB84 like protocol, which utilizes time and frequency as complementary bases. As orthogonal modulations, pulse position modulation (PPM) and…

The extraction of information carried by light plays an increasingly important role in optical communication, imaging, and detection. However, the information can only be successfully extracted when the light pulse is comparably strong,…

Optics · Physics 2026-05-25 Zhen Yang , Zeng-Quan Yan , Li Wang , Xiao-Wei Wang , Ka-Di Zhu , Xian-Min Jin

We study the coherent storage and retrieval of a very short multimode light pulse in an atomic ensemble. We consider a quantum memory process based on the conversion of a signal pulse into a long-lived spin coherence via light matter…

Quantum Physics · Physics 2011-05-27 T. Golubeva , Yu. Golubev , O. Mishina , A. Bramati , J. Laurat , E. Giacobino

We discuss the various manifestations of quantum decoherence in the forms of dephasing, entanglement with the environment, and revelation of "which-path" information. As a specific example, we consider an electron interference experiment.…

Quantum Physics · Physics 2015-05-13 Jen-Tsung Hsiang , L. H. Ford

In all lossy communication channels realized to date, information is inevitably leaked to a potential eavesdropper. Here we present a communication protocol that does not allow for any information leakage to a potential eavesdropper in a…

A transducer capable of converting quantum information stored as microwaves into telecom-wavelength signals is a critical piece of future quantum technology as it promises to enable the networking of quantum processors. Cavity…

Applied Physics · Physics 2019-09-25 M. J. Rudd , P. H. Kim , C. A. Potts , C. Doolin , H. Ramp , B. D. Hauer , J. P. Davis

We study non-asymptotic fundamental limits for transmitting classical information over memoryless quantum channels, i.e. we investigate the amount of classical information that can be transmitted when a quantum channel is used a finite…

Quantum Physics · Physics 2015-05-20 Marco Tomamichel , Vincent Y. F. Tan

We develop an enhanced technique for characterizing quantum optical processes based on probing unknown quantum processes only with coherent states. Our method substantially improves the original proposal [M. Lobino et al., Science 322, 563…

Werner states have a host of interesting properties, which often serve to illuminate the unusual properties of quantum information. Starting from these states, one may define a family of quantum channels, known as the Holevo-Werner…

Quantum Physics · Physics 2018-11-15 Thomas P. W. Cope , Kenneth Goodenough , Stefano Pirandola

Control over intensity, shape, direction, and phase of coherent light is essential in numerous fields, reaching from gravitational wave astronomy over quantum metrology and ultrafast sciences to semi-conductor fabrication. Modern laser…

Characterizing the ultimate rates of entanglement distribution is essential for both foundational research and the practical deployment of quantum technologies. To investigate these limits, we introduce an erasure-Pauli channel model…

Quantum Physics · Physics 2026-03-06 Stefano Pirandola

Deterministic optical quantum logic requires a nonlinear quantum process that alters the phase of a quantum optical state by $\pi$ through interaction with only one photon. Here, we demonstrate a large conditional cross-phase modulation…

Quantum Physics · Physics 2017-09-13 Kristin M. Beck , Mahdi Hosseini , Yiheng Duan , Vladan Vuletić

A long-standing problem on the classical capacity of bosonic Gaussian channels has recently been resolved by proving the minimum output entropy conjecture. It is also known that the ultimate capacity quantified by the Holevo bound can be…

Quantum Physics · Physics 2015-05-07 Jaehak Lee , Se-Wan Ji , Jiyong Park , Hyunchul Nha

The main conceptual contribution of this paper is investigating quantum multiparty communication complexity in the setting where communication is \emph{oblivious}. This requirement, which to our knowledge is satisfied by all quantum…

Quantum Physics · Physics 2023-12-29 François Le Gall , Daiki Suruga

The analysis of optical pulse generation by phase modulation of narrowband continuous-wave light, and subsequent propagation through a group-delay-dispersion circuit, is usually performed in terms of the so-called bunching parameter. This…

Optics · Physics 2009-11-11 Victor Torres-Company , Jesus Lancis , Pedro Andres

The photonic temporal degree of freedom is one of the most promising platforms for quantum communication over fiber networks and free-space channels. In particular, time-bin states of photons are robust to environmental disturbances,…

We investigate the potential of atomic Bose-Einstein condensates as dynamic memory devices for coherent optical information processing. Specifically, the number of ultraslow pulses that can be simultaneously present within the storage time…

Other Condensed Matter · Physics 2009-09-29 Devrim Tarhan , Alphan Sennaroglu , Ozgur E. Mustecaplioglu

We derive several efficiently computable converse bounds for quantum communication over quantum channels in both the one-shot and asymptotic regime. First, we derive one-shot semidefinite programming (SDP) converse bounds on the amount of…

Quantum Physics · Physics 2019-05-06 Xin Wang , Kun Fang , Runyao Duan