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

Quantum coherent absorption of squeezed light

Ali Ü. C. Hardal, Martijn Wubs

Published Jan 1, 2019• 24 citations
OpenAlex

Abstract

Two identical squeezed coherent states at the input ports of a 50% absorbing beam splitter do not show coherent perfect absorption (CPA). All coherence is lost, though, since at the output ports entangled squeezed vacuum states emerge. Remarkably, this output state is a pure state, although produced by a lossy device. Therefore this CPA gate could become a new tool for continuous-variable quantum state preparation. Moreover, for graphene multilayers engineered for CPA, we discuss the effects of interlayer separation.

Related papers

Preparing pure states with lossy beam splitters using quantum coherent absorption of squeezed light

Martijn Wubs, Ali Ü. C. Hardal

We investigate coherent perfect absorption (CPA) of squeezed coherent states of light by an absorbing beam splitter. First we derive the absorption coefficients for quantum coherence and for intensity, which generally differ. Secondly, we present the remarkable properties of a CPA-gate: two identical but otherwise arbitrary incoming squeezed coherent states can be completely stripped off their coherence, producing a pure entangled squeezed vacuum state at the output. Importantly, this output state of light is not entangled with the absorbing beam splitter by which it was produced. This makes the CPA gate potentially interesting for continuous-variable quantum state preparation.

Quantum Nanophotonic Materials, Devices, and Systems•Sep 3, 2019•0 citations

Quantum coherent absorption of squeezed light

A. Ü. C. Hardal, Martijn Wubs

We investigate coherent perfect absorption (CPA) in quantum optics, in particular when pairs of squeezed coherent states of light are superposed on an absorbing beam splitter. First, by employing quantum optical input-output relations, we derive the absorption coefficients for quantum coherence and for intensity, and reveal how these will differ for squeezed states. Secondly, we present the remarkable properties of a CPA-gate: two identical but otherwise arbitrary incoming squeezed coherent states can be completely stripped off their coherence, producing a pure entangled squeezed vacuum state that with its finite intensity escapes from an otherwise perfect absorber. Importantly, this output state of light is not entangled with the absorbing beam splitter by which it was produced. Its loss-enabled functionality makes the CPA gate an interesting new tool for continuous-variable quantum state preparation.

arXiv:1805.02884•Optica•Feb 7, 2019•26 citations

Coherent perfect absorption of quantum light

Anton N. Vetlugin

Coherent perfect absorption (CPA) was introduced as a classical optics phenomenon of a standing-wave absorption by a subwavelength film. In this paper, we develop a theory of CPA of quantized standing waves taking account of a subwavelength thickness of the absorber. This approach allows us to merge all known quantum effects of CPA under a single theory and introduce other regimes of CPA including CPA of NOON states with arbitrary number of entangled photons, orthogonally squeezed vacuum states, continuous variable entangled states, and Schr\"odinger cat states. Detailed analysis of the quantum regime of CPA sheds light on fundamental aspects of quantum light dissipation and its practical implementation in quantum optics and quantum information.

arXiv:2101.02372•Physical Review A•Jul 20, 2021•31 citations

Coherent control of light-matter interactions in metamaterials: absorption and beyond

Jianfa Zhang

In the past few years, a new phenomenon of absorption, called “coherent perfect absorption (CPA)”, has attracted significant attentions [1, 2]. CPA relies on the coherent interference of light. In a typical CPA system, two coherent beams are incident on the absorber from opposite sides and the reflected light of one beam interfere with the transmitted light of the other and vice versa. CPA was first realized using a silicon slab cavity, and has then been reported in composite absorptive films, planar metamaterials, graphene, waveguides and so on.

Progress in Electromagnetic Research Symposium•Aug 1, 2016•1 citation

Quantum optics of lossy beam splitters

Stephen Mark Barnett, John Jeffers, A. Gatti +1 more

The familiar input-output relations for an optical beam splitter are generalized to allow for linear absorption by the medium forming the mirror. Beam-splitter losses generally affect the noise levels detectable in experiments involving nonclassical light. When employed to investigate two-photon interference effects, a lossy beam splitter can lead to apparent nonlinear absorption, which, in the most extreme case, leads to either both or neither of the photons being absorbed. The degree of second-order coherence of antibunched light can be maintained on transmission through the beam splitter but any amplitude squeezing in the incident light is degraded.

Physical Review A•Mar 1, 1998•184 citations

Engineering vacuum-evacuated photonic states with three input beams and two detectors

Sun-Hyun Youn

From the explicit form of the probability amplitude for two cascade-placed beam splitters (with one squeezed state input and two coherent state inputs), we calculated the probability amplitude of the output beam as a function of the transmittance of the two beam splitters and the amplitude and the relative phase of the three input states. At a certain condition, the output beam had no vacuum and was in a highly nonclassical state that contained more than one photon. Armed with explicit probability amplitude for two beam splitters and two coherent states, the squeezed vacuum state might be a very useful tool for generating highly nonclassical light.

Journal of the Korean Physical Society•Oct 1, 2013•4 citations
Two identical squeezed coherent states at the input ports of a 50% absorbing beam splitter do not show coherent perfect absorption (CPA). All coherence is lost, though, since at the output ports entangled squeezed vacuum states emerge. Remarkably, this output state is a pure state, although produced by a lossy device. Therefore this CPA gate could become a new tool for continuous-variable quantum state preparation. Moreover, for graphene multilayers engineered for CPA, we discuss the effects of interlayer separation.
We investigate coherent perfect absorption (CPA) of squeezed coherent states of light by an absorbing beam splitter. First we derive the absorption coefficients for quantum coherence and for intensity, which generally differ. Secondly, we present the remarkable properties of a CPA-gate: two identical but otherwise arbitrary incoming squeezed coherent states can be completely stripped off their coherence, producing a pure entangled squeezed vacuum state at the output. Importantly, this output state of light is not entangled with the absorbing beam splitter by which it was produced. This makes the CPA gate potentially interesting for continuous-variable quantum state preparation.
We investigate coherent perfect absorption (CPA) in quantum optics, in particular when pairs of squeezed coherent states of light are superposed on an absorbing beam splitter. First, by employing quantum optical input-output relations, we derive the absorption coefficients for quantum coherence and for intensity, and reveal how these will differ for squeezed states. Secondly, we present the remarkable properties of a CPA-gate: two identical but otherwise arbitrary incoming squeezed coherent states can be completely stripped off their coherence, producing a pure entangled squeezed vacuum state that with its finite intensity escapes from an otherwise perfect absorber. Importantly, this output state of light is not entangled with the absorbing beam splitter by which it was produced. Its loss-enabled functionality makes the CPA gate an interesting new tool for continuous-variable quantum state preparation.
Coherent perfect absorption (CPA) was introduced as a classical optics phenomenon of a standing-wave absorption by a subwavelength film. In this paper, we develop a theory of CPA of quantized standing waves taking account of a subwavelength thickness of the absorber. This approach allows us to merge all known quantum effects of CPA under a single theory and introduce other regimes of CPA including CPA of NOON states with arbitrary number of entangled photons, orthogonally squeezed vacuum states, continuous variable entangled states, and Schr\"odinger cat states. Detailed analysis of the quantum regime of CPA sheds light on fundamental aspects of quantum light dissipation and its practical implementation in quantum optics and quantum information.
In the past few years, a new phenomenon of absorption, called “coherent perfect absorption (CPA)”, has attracted significant attentions [1, 2]. CPA relies on the coherent interference of light. In a typical CPA system, two coherent beams are incident on the absorber from opposite sides and the reflected light of one beam interfere with the transmitted light of the other and vice versa. CPA was first realized using a silicon slab cavity, and has then been reported in composite absorptive films, planar metamaterials, graphene, waveguides and so on.
The familiar input-output relations for an optical beam splitter are generalized to allow for linear absorption by the medium forming the mirror. Beam-splitter losses generally affect the noise levels detectable in experiments involving nonclassical light. When employed to investigate two-photon interference effects, a lossy beam splitter can lead to apparent nonlinear absorption, which, in the most extreme case, leads to either both or neither of the photons being absorbed. The degree of second-order coherence of antibunched light can be maintained on transmission through the beam splitter but any amplitude squeezing in the incident light is degraded.
From the explicit form of the probability amplitude for two cascade-placed beam splitters (with one squeezed state input and two coherent state inputs), we calculated the probability amplitude of the output beam as a function of the transmittance of the two beam splitters and the amplitude and the relative phase of the three input states. At a certain condition, the output beam had no vacuum and was in a highly nonclassical state that contained more than one photon. Armed with explicit probability amplitude for two beam splitters and two coherent states, the squeezed vacuum state might be a very useful tool for generating highly nonclassical light.