A5081869552- Quantum Information and Cryptography
- Quantum optics and atomic interactions
- Quantum Mechanics and Applications
- Quantum Computing Algorithms and Architecture
- Photonic and Optical Devices
- Neural Networks and Reservoir Computing
- Mechanical and Optical Resonators
- Optical Network Technologies
- Advanced Fiber Laser Technologies
- Cold Atom Physics and Bose-Einstein Condensates
- Photorefractive and Nonlinear Optics
- Pulsars and Gravitational Waves Research
- Geophysics and Sensor Technology
- Atomic and Subatomic Physics Research
- Laser-Matter Interactions and Applications
- Photochemistry and Electron Transfer Studies
- Quantum and electron transport phenomena
- Advanced Optical Sensing Technologies
- Spectroscopy and Quantum Chemical Studies
- Advanced Frequency and Time Standards
- Nuclear Physics and Applications
- Rare-earth and actinide compounds
- Spectroscopy Techniques in Biomedical and Chemical Research
- Force Microscopy Techniques and Applications
- Thermodynamic and Structural Properties of Metals and Alloys
The University of Tokyo
2015-2024
RIKEN Center for Quantum Computing
2021-2024
RIKEN Center for Advanced Photonics
2021-2024
Nitto RIKEN (Japan)
2024
Computing Center
2023-2024
Kagoshima University
2018
Centre for Quantum Computation and Communication Technology
2016
UNSW Sydney
2016
United States Geological Survey
2013
Japan Science and Technology Agency
2004-2009
Quantum teleportation of optical coherent states was demonstrated experimentally using squeezed-state entanglement. The quantum nature the achieved verified by determined fidelity Fexp = 0.58 +/- 0.02, which describes match between input and output states. A greater than 0.5 is not possible for without use This first realization unconditional where every state entering device actually teleported.
We derive necessary conditions in terms of the variances position and momentum linear combinations for all kinds separability a multi-party multi-mode continuous-variable state. Their violations can be sufficient genuine multipartite entanglement, provided contain both conjugate variables modes. Hence complete state determination, example by detecting entire correlation matrix Gaussian state, is not needed.
Entanglement is the key resource for measurement-based quantum computing. It stored in states known as cluster states, which are prepared offline and enable computing by means of purely local measurements. Universal requires that both large possess (at least) a two-dimensional topology. Continuous-variable states-based on bosonic modes rather than qubits-have previously been generated scale exceeding one million modes, but only dimension. Here, we report generation large-scale...
In recent quantum optical continuous-variable experiments, the number of fully inseparable light modes has drastically increased by introducing a multiplexing scheme either in time domain or frequency domain. Here, modifying time-domain experiment reported Nature Photonics 7, 982 (2013), we demonstrate successive generation for more than one million modes. The resulting multi-mode state is useful as dual-rail CV cluster state. We circumvent previous problem phase drifts, which limited to...
To harness the potential of a quantum computer, information must be protected against error by encoding it into logical state that is suitable for correction. The Gottesman-Kitaev-Preskill (GKP) qubit promising candidate because required multiqubit operations are readily available at optical frequency. date, however, GKP qubits have been demonstrated only mechanical and microwave frequencies. We realized in propagating light telecommunication wavelength verified through homodyne measurements...
We report measurements of cavity-QED effects for the radiative coupling atoms in a dilute vapor to external evanescent field whispering-gallery mode (WGM) fused silica microsphere. The high $Q$ $(5\ifmmode\times\else\texttimes\fi{}{10}^{7})$, small volume (10${}^{\ensuremath{-}8}$ cm${}^{3})$, and unusual symmetry microcavity enable velocity-selective interactions between fields with photon number order unity WGM ${N}_{T}\ensuremath{\sim}1$ surrounding vapor.
We present controllable generation of various kinds highly nonclassical states light, including the single photon state and superposition mesoscopically distinct components. The high nonclassicality generated is measured by negativity Wigner function, which largest ever observed to our knowledge. Our scheme based on subtraction from a nearly pure squeezed vacuum, an optical parametric oscillator with periodically-poled KTiOPO$_4$ crystal as nonlinear medium. This important step realize basic...
A continuous-variable tripartite entangled state is experimentally generated by combining three independent squeezed vacuum states, and the variances of its relative positions total momentum are measured. We show that measured values violate separability criteria based on sum these quantities prove full inseparability state.
Storage and retrieval of a squeezed vacuum was successfully demonstrated using electromagnetically induced transparency. The pulse having temporal width 930 ns incident on the laser cooled $^{87}\mathrm{Rb}$ atoms with an intense control light in coherent state. When slowed spatially compressed cold atoms, switched off. After $3\text{ }\text{ }\ensuremath{\mu}\mathrm{s}$ storage, again, retrieved, as confirmed time-domain homodyne method.
We experimentally demonstrate continuous-variable quantum teleportation beyond the no-cloning limit. teleport a coherent state and achieve fidelity of 0.70 +/- 0.02 that surpasses limit 2/3. Surpassing is necessary to transfer nonclassicality an input state. By using our high-fidelity teleporter, we entanglement swapping, namely, entanglement, as example nonclassicality.
We propose and demonstrate a novel method to generate large-amplitude coherent-state superposition (CSS) via ancilla-assisted photon subtraction. The ancillary mode induces quantum interference of indistinguishable processes in an extended space, widening the controllability at conditional output. this by simple time-separated two-photon subtraction from continuous wave squeezed light. observe largest CSS traveling light ever reported without correcting any imperfections, which will enable...
Continuous-variable Gaussian cluster states are a potential resource for universal quantum computation. They can be efficiently and unconditionally built from sources of squeezed light using beam splitters. Here we report on the generation three different kinds continuous-variable four-mode states. In our realization, resulting cluster-type correlations such that no corrections other than simple phase-space displacements would needed when information propagates through these At same time,...
We report on the experimental quantum teleportation of strongly nonclassical wave packets light. To perform this full operation while preserving and retrieving fragile nonclassicality input state, we have developed a broadband, zero-dispersion apparatus that works in conjunction with time-resolved state preparation equipment. Our approach brings within reach whole new set hybrid protocols involving discrete- continuous-variable techniques information processing for optical sciences.
Tracking a randomly varying optical phase is key task in metrology, with applications communication. The best precision for tracking has till now been limited by the quantum vacuum fluctuations of coherent light. Here we surpass this coherent-state limit using continuous-wave beam phase-squeezed state. Unlike previous squeezing-enhanced restricted to phases very small variation, (for fixed light intensity) achieved finite degree squeezing, due Heisenberg's uncertainty principle. By...
We observe -9.01+/-0.14 dB of squeezing and +15.12+/-0.14 antisqueezing with a local oscillator phase locked in homodyne measurement. Suzuki et al. have pointed out two main factors [Appl. Phys. Lett. 89, 061116 (2006)], which degrade the observed level:phase fluctuation measurement intracavity losses an optical parametric for squeezing. improved stability reduced losses. measure pump power dependences levels, show good agreement theoretical calculations taking account fluctuation.
We develop an experimental scheme based on a continuous-wave (cw) laser for generating arbitrary superpositions of photon number states. In this experiment, we successfully generate superposition states zero to three photons, namely advanced versions two and coherent They are fully compatible with developed quantum teleportation measurement-based operations cw lasers. Due achieved high detection efficiency, observe, without any loss correction, multiple areas negativity Wigner function,...
One-way quantum computation is a very promising candidate to fulfill the capabilities of information processing. Here we demonstrate an important set unitary operations for continuous variables using linear cluster state four entangled optical modes. These are performed in fully measurement-controlled and completely unconditional fashion. We implement three different levels squeezing Fourier transformation, all which accessible by selecting correct quadrature measurement angles homodyne...