Recently, the delayed-choice quantum eraser has been applied for coherently excited superresoluti... more Recently, the delayed-choice quantum eraser has been applied for coherently excited superresolution using phasecontrolled projection measurements of laser light to overcome the diffraction limit in classical physics as well as to solve the limited photon number of the N00N state in quantum physics. Unlike other methods of phasecontrolled superresolution in a noninterferometric system, the proposed method is for the intensity products between phase-controlled quantum erasers, resulting in superresolution compatible with the most conventional sensing metrologies. Here, a general scheme of the phase-controlled quantum eraser-based superresolution is proposed and its general solution is derived for an arbitrary N th-order intensity correlation, where the superresolution shows the photonic de Broglie wave-like quantum feature. Furthermore, phase quantization of the superresolution is discussed to better understand quantum mechanics.
Franson-type nonlocal correlation is related to Bell inequality violation tests and has been appl... more Franson-type nonlocal correlation is related to Bell inequality violation tests and has been applied for quantum key distributions based on time bin methods. Using unbalanced Mach-Zehnder interferometers, Franson correlation measurements result in an interference fringe, while local measurements do not. Here, randomness-based macroscopic Franson-type correlation is presented using polarization-based two-mode coherent photons, where the quantum correlation is tested by a Hong-Ou-Mandel scheme. Coherent photons are used to investigate the wave properties of this correlation. Without contradicting the wave-particle duality of quantum mechanics, the proposed method provides fundamental understanding of the quantum nature and opens the door to deterministic quantum information science.
Quantum superposition is normally sustained in a microscopic regime governed by Heisenberg’s unce... more Quantum superposition is normally sustained in a microscopic regime governed by Heisenberg’s uncertainty principle applicable to a single particle. Quantum correlation between paired particles implies the violation of local realism governed by classical physics. Over the last decades, quantum features have been implemented in various quantum technologies including quantum computing, communications, and sensing. Such quantum features are generally known to be impossible by any classical means. Here, a macroscopic quantum correlation is presented for coherence manipulations of polarization-path correlations of a continuous wave laser, satisfying the joint-parameter relation in an inseparable product-basis form. For the coherence control of the polarization-path correlation, a pair of electro-optic modulators is used in a noninterfering Mach-Zehnder interferometer for deterministic switching between paired polarization bases, resulting in the polarization product-basis superposition in...
Nonlocal quantum correlation has been the main issue of quantum mechanics over the last century. ... more Nonlocal quantum correlation has been the main issue of quantum mechanics over the last century. The Hong-Ou-Mandel (HOM) effect relates to the two-photon intensity correlation on a beam splitter, resulting in a nonclassical photon-bunching phenomenon. The HOM effect has been used to verify the quantum feature via Bell measurements for quantum technologies such as quantum repeaters and photonics quantum computing. Here, a coherence version of the HOM effect is proposed and analyzed to understand the fundamental physics of the anticorrelation and entanglement. For this, frequency-correlated coherent photon pairs are prepared in an independent set of Mach-Zhender interferometers (MZI) using a synchronized pair of modulators from an attenuated laser. For the HOM effect, the phase relation between frequency-correlated photons plays an essential role. For the product-basis randomness, the symmetrically modulated two independent MZIs are combined together incoherently. A classical intensity product between two independent photodetectors is also discussed for the same HOM effect in a selective macroscopic measurement scheme.
In this paper, we propose and demonstrate a scheme to enhance nonlinearities of a probe pulse at ... more In this paper, we propose and demonstrate a scheme to enhance nonlinearities of a probe pulse at both cross-phase modulation (XPM) and self-phase modulation (SPM) in a four-level system. Based on standing wave grating generated by counter-propagating resonant signal fields and an additional off-resonant coupling field, a giant nonlinear refractive index of the resonant probe field is obtained with absorption suppressed. Group velocity of the probe pulse can be controlled by both XPM and SPM nonlinearities.
Bell inequality violation is a quantitative measurement tool of quantum entanglement between spac... more Bell inequality violation is a quantitative measurement tool of quantum entanglement between space-like separated particles. Quantum entanglement is the heart of quantum information science, in which the resulting nonlocal correlation between the paired particles is a unique property of quantum mechanics. Over the last few decades, intensive research has been conducted to understand nonlocal quantum features based on the particle nature of quantum mechanics. Here, the role of coincidence detection is analyzed in a simple interferometer using a quantum eraser. To understand the nonlocal quantum feature, coincidence detection between two output photons of an interferometer is coherently analyzed for Bell inequality violations. Based on this understanding, a classical model of the nonlocal quantum correlation is finally presented using coherent light via wave mixing and heterodyne detection.
Journal of Physics B: Atomic, Molecular and Optical Physics, 2009
We report the observations of Mollow sideband-like transparency windows in a Doppler-broadened fo... more We report the observations of Mollow sideband-like transparency windows in a Doppler-broadened four-level N-type system of the rubidium D2 line. A pair of enhanced transparency windows across an electromagnetically induced transparency line centre results from dressed state interactions of two coupling fields. The present observations have potential applications of using the symmetric transparency windows for optical quantum information processing such
We have studied stationary and quasi-stationary signal light pulses in cold -type atomic media d... more We have studied stationary and quasi-stationary signal light pulses in cold -type atomic media driven by counterpropagating control laser fields at the condition of electromagnetically induced transparency. By deriving a dispersion relation we present spectral and temporal properties of the signal light pulse and a significant influence of atomic decoherence on the coupled stationary light pulses for spatial splitting. Finally we discuss quasi-stationary light pulse evolution characterized by frozen spatial spreading for a robust coherent control of slow light pulses.
Journal of Optics B: Quantum and Semiclassical Optics, 2003
... Let us assume that the medium consists of atoms of two sorts, with the concentrationCa of &am... more ... Let us assume that the medium consists of atoms of two sorts, with the concentrationCa of 'a'-atoms being much smaller than the concentration Cb of 'b'-atoms (Ca ≪ Cb, Ca,b = Na,b/V; Na , Nb are the macroscopic values, V is the volume). ...
Recently, the delayed-choice quantum eraser has been applied for coherently excited superresoluti... more Recently, the delayed-choice quantum eraser has been applied for coherently excited superresolution using phasecontrolled projection measurements of laser light to overcome the diffraction limit in classical physics as well as to solve the limited photon number of the N00N state in quantum physics. Unlike other methods of phasecontrolled superresolution in a noninterferometric system, the proposed method is for the intensity products between phase-controlled quantum erasers, resulting in superresolution compatible with the most conventional sensing metrologies. Here, a general scheme of the phase-controlled quantum eraser-based superresolution is proposed and its general solution is derived for an arbitrary N th-order intensity correlation, where the superresolution shows the photonic de Broglie wave-like quantum feature. Furthermore, phase quantization of the superresolution is discussed to better understand quantum mechanics.
Franson-type nonlocal correlation is related to Bell inequality violation tests and has been appl... more Franson-type nonlocal correlation is related to Bell inequality violation tests and has been applied for quantum key distributions based on time bin methods. Using unbalanced Mach-Zehnder interferometers, Franson correlation measurements result in an interference fringe, while local measurements do not. Here, randomness-based macroscopic Franson-type correlation is presented using polarization-based two-mode coherent photons, where the quantum correlation is tested by a Hong-Ou-Mandel scheme. Coherent photons are used to investigate the wave properties of this correlation. Without contradicting the wave-particle duality of quantum mechanics, the proposed method provides fundamental understanding of the quantum nature and opens the door to deterministic quantum information science.
Quantum superposition is normally sustained in a microscopic regime governed by Heisenberg’s unce... more Quantum superposition is normally sustained in a microscopic regime governed by Heisenberg’s uncertainty principle applicable to a single particle. Quantum correlation between paired particles implies the violation of local realism governed by classical physics. Over the last decades, quantum features have been implemented in various quantum technologies including quantum computing, communications, and sensing. Such quantum features are generally known to be impossible by any classical means. Here, a macroscopic quantum correlation is presented for coherence manipulations of polarization-path correlations of a continuous wave laser, satisfying the joint-parameter relation in an inseparable product-basis form. For the coherence control of the polarization-path correlation, a pair of electro-optic modulators is used in a noninterfering Mach-Zehnder interferometer for deterministic switching between paired polarization bases, resulting in the polarization product-basis superposition in...
Nonlocal quantum correlation has been the main issue of quantum mechanics over the last century. ... more Nonlocal quantum correlation has been the main issue of quantum mechanics over the last century. The Hong-Ou-Mandel (HOM) effect relates to the two-photon intensity correlation on a beam splitter, resulting in a nonclassical photon-bunching phenomenon. The HOM effect has been used to verify the quantum feature via Bell measurements for quantum technologies such as quantum repeaters and photonics quantum computing. Here, a coherence version of the HOM effect is proposed and analyzed to understand the fundamental physics of the anticorrelation and entanglement. For this, frequency-correlated coherent photon pairs are prepared in an independent set of Mach-Zhender interferometers (MZI) using a synchronized pair of modulators from an attenuated laser. For the HOM effect, the phase relation between frequency-correlated photons plays an essential role. For the product-basis randomness, the symmetrically modulated two independent MZIs are combined together incoherently. A classical intensity product between two independent photodetectors is also discussed for the same HOM effect in a selective macroscopic measurement scheme.
In this paper, we propose and demonstrate a scheme to enhance nonlinearities of a probe pulse at ... more In this paper, we propose and demonstrate a scheme to enhance nonlinearities of a probe pulse at both cross-phase modulation (XPM) and self-phase modulation (SPM) in a four-level system. Based on standing wave grating generated by counter-propagating resonant signal fields and an additional off-resonant coupling field, a giant nonlinear refractive index of the resonant probe field is obtained with absorption suppressed. Group velocity of the probe pulse can be controlled by both XPM and SPM nonlinearities.
Bell inequality violation is a quantitative measurement tool of quantum entanglement between spac... more Bell inequality violation is a quantitative measurement tool of quantum entanglement between space-like separated particles. Quantum entanglement is the heart of quantum information science, in which the resulting nonlocal correlation between the paired particles is a unique property of quantum mechanics. Over the last few decades, intensive research has been conducted to understand nonlocal quantum features based on the particle nature of quantum mechanics. Here, the role of coincidence detection is analyzed in a simple interferometer using a quantum eraser. To understand the nonlocal quantum feature, coincidence detection between two output photons of an interferometer is coherently analyzed for Bell inequality violations. Based on this understanding, a classical model of the nonlocal quantum correlation is finally presented using coherent light via wave mixing and heterodyne detection.
Journal of Physics B: Atomic, Molecular and Optical Physics, 2009
We report the observations of Mollow sideband-like transparency windows in a Doppler-broadened fo... more We report the observations of Mollow sideband-like transparency windows in a Doppler-broadened four-level N-type system of the rubidium D2 line. A pair of enhanced transparency windows across an electromagnetically induced transparency line centre results from dressed state interactions of two coupling fields. The present observations have potential applications of using the symmetric transparency windows for optical quantum information processing such
We have studied stationary and quasi-stationary signal light pulses in cold -type atomic media d... more We have studied stationary and quasi-stationary signal light pulses in cold -type atomic media driven by counterpropagating control laser fields at the condition of electromagnetically induced transparency. By deriving a dispersion relation we present spectral and temporal properties of the signal light pulse and a significant influence of atomic decoherence on the coupled stationary light pulses for spatial splitting. Finally we discuss quasi-stationary light pulse evolution characterized by frozen spatial spreading for a robust coherent control of slow light pulses.
Journal of Optics B: Quantum and Semiclassical Optics, 2003
... Let us assume that the medium consists of atoms of two sorts, with the concentrationCa of &am... more ... Let us assume that the medium consists of atoms of two sorts, with the concentrationCa of 'a'-atoms being much smaller than the concentration Cb of 'b'-atoms (Ca ≪ Cb, Ca,b = Na,b/V; Na , Nb are the macroscopic values, V is the volume). ...
Uploads
Papers by Byoung S Ham