Publications (227)
Entanglement-based continuous-variable quantum key distribution with multimode states and detectors
Vladyslav C. Usenko, Laszlo Ruppert, Radim Filip
Secure quantum key distribution with multimode Gaussian entangled states and multimode homodyne detectors is proposed. In general the multimode character of both the sources of ent…
Efficiency vs. multi-photon contribution test for quantum dots
Ana Predojevic, Miroslav Jezek, Tobias Huber +5
The development of linear quantum computing within integrated circuits demands high quality semiconductor single photon sources. In particular, for a reliable single photon source…
Efficient OPA tomography of non-Gaussian states of light
Ãva Rácz, László Ruppert, Radim Filip
Current advances in nonlinear optics have made it possible to perform a homodyne-like tomography of an unknown state without highly efficient detectors or a strong local oscillator…
Noise-Powered Probabilistic Concentration of Phase Information
Mario A. Usuga, Christian R. Mueller, Christoffer Wittmann +5
Phase insensitive optical amplification of an unknown quantum state is known to be a fundamentally noisy operation that inevitably adds noise to the amplified state [1 - 5]. Howeve…
Nonlinear stochastic and quantum motion from Coulomb forces
Luca Ornigotti, Darren W. Moore, Radim Filip
Controllable nonlinear quantum interactions are a much sought after target for modern quantum technologies. They are typically difficult and costly to engineer for bespoke purposes…
Nonlocal quantum gate on quantum continuous variables with minimum resources
Shota Yokoyama, Ryuji Ukai, Jun-ichi Yoshikawa +3
We experimentally demonstrate, with an all-optical setup, a nonlocal deterministic quantum non-demolition interaction gate applicable to quantum states at nodes separated by a phys…
Qubit-parity interference despite unknown interaction phases
Kratveer Singh, Kimin Park, VojtÄch Å varc +5
Quantum interference between interacting systems is fundamental to basic science and quantum technology, but it typically requires precise control of the interaction phases of lase…
Stroboscopic high-order nonlinearity for quantum optomechanics
Andrey A. Rakhubovsky, Radim Filip
High-order quantum nonlinearity is an important prerequisite for the advanced quantum technology leading to universal quantum processing with large information capacity of continuo…
Heralded Source of Bright Multi-mode Mesoscopic Sub-Poissonian Light
Timur Sh. Iskhakov, Vladyslav C. Usenko, Ulrik L. Andersen +3
In a direct detection scheme we observed 7.8 dB of twin-beam squeezing for multi-mode two-color squeezed vacuum generated via parametric down conversion. Applying post-selection, w…
Experimental certification of level dynamics in single-photon emitters
Luk\' aš Lachman, Ilya P. Radko, Maxime Bergamin +2
Emitters of single-photons are essential resources for emerging quantum technologies and developed within different platforms including nonlinear optics, atomic and solid-state sys…
Cross talk compensation in multimode continuous-variable entanglement distribution
Olena Kovalenko, Vladyslav C. Usenko, Radim Filip
Two-mode squeezed states are scalable and robust entanglement resources for continuous-variable and hybrid quantum information protocols at a distance. We consider the effect of a…
Entanglement of Gaussian states and the applicability to quantum key distribution over fading channels
Vladyslav C. Usenko, Bettina Heim, Christian Peuntinger +4
Entanglement properties of Gaussian states of light as well as the security of continuous variable quantum key distribution with Gaussian states in free-space fading channels are s…
Quantum non-Gaussian Photon Coincidences
Lukáš Lachman, Radim Filip
Photon coincidences represent an important resource for quantum technologies. They expose nonlinear quantum processes in matter and are essential for sources of entanglement. We de…
Taming numerical errors in simulations of continuous variable non-Gaussian state preparation
Jan ProvaznÃk, Radim Filip, Petr Marek
Numerical simulation of continuous variable quantum state preparation is a necessary tool for optimization of existing quantum information processing protocols. A powerful instrume…
Frequency multiplexed entanglement for continuous-variable quantum key distribution
Olena Kovalenko, Young-Sik Ra, Yin Cai +4
Quantum key distribution with continuous variables already uses advantageous high-speed single-mode homodyne detection with low electronic noise at room temperature. Together with…
Tunable phonon induced steady state coherence in a double quantum dot
Archak Purkayastha, Giacomo Guarnieri, Mark T. Mitchison +2
Charge qubits can be created and manipulated in solid-state double-quantum-dot (DQD) platforms. Typically, these systems are strongly affected by quantum noise stemming from coupli…
Qubit-environment entanglement in time-dependent pure dephasing
MaÅgorzata StrzaÅka, Radim Filip, Katarzyna Roszak
We show that the methods for quantification of system-environment entanglement that were recently developed for interactions that lead to pure decoherence of the system can be stra…
Quantum non-Gaussianity from a large ensemble of single photon emitters
Lukáš Lachman, Radim Filip
Quantum attributes of light have been related to non-classicality so far, i. e. to incompatibility with mixtures of coherent states. The progress in quantum optics indicates that t…
Stationary Gaussian Entanglement between Levitated Nanoparticles
Anil Kumar Chauhan, OndÅej ÄernotÃk, Radim Filip
Coherent scattering of photons is a novel mechanism of optomechanical coupling for optically levitated nanoparticles promising strong, versatile interactions with light and between…
Experimental realization of a dynamic squeezing gate
Kazunori Miyata, Hisashi Ogawa, Petr Marek +4
Squeezing is a nonlinear Gaussian operation that is the key component in construction of other nonlinear Gaussian gates. In our implementation of the squeezing gate, the amount and…
Steady-state coherences by composite system-bath interactions
Giacomo Guarnieri, Michal Kolar, Radim Filip
We identify sufficient conditions on the structure of the interaction Hamiltonian between a two-level quantum system and a thermal bath which, without any external drive or coheren…
Phase-selective reversible quantum decoherence in cavity QED experiment
Radim Filip
New feasible cavity QED experiment is proposed to analyse reversible quantum decoherence in consequence of quantum complementarity and entanglement. Utilizing the phase selective m…
Quantum non-Gaussianity criteria based on vacuum probabilities of original and attenuated state
JaromÃr Fiurášek, Lukáš Lachman, Radim Filip
Quantum non-Gaussian states represent an important class of highly non-classical states whose preparation requires quantum operations or measurements beyond the class of Gaussian o…
A many-particle bosonic quantum Maxwell demon
Josef HlouÅ¡ek, Tobias Denzler, VojtÄch Å varc +3
Energy extraction from a measured quantum system is a cornerstone of information thermodynamics as illustrated by Maxwell's demon. The nonequilibrium physics of many-particle syste…
Tuneable Gaussian entanglement in levitated nanoparticle arrays
Anil Kumar Chauhan, OndÅej ÄernotÃk, Radim Filip
Nanoparticles trapped in optical tweezers emerged as an interesting platform for investigating fundamental effects in quantum physics. The ability to shape the optical trapping pot…
Entanglement growth via splitting of a few thermal quanta
Pradip Laha, Darren W. Moore, Radim Filip
Quanta splitting is an essential generator of Gaussian entanglement, exemplified by Einstein-Podolsky-Rosen states and apparently the most commonly occurring form of entanglement.…
Squeezer-based pulsed optomechanical interface
Andrey A. Rakhubovsky, Nikita Vostrosablin, Radim Filip
We prove feasibility of high-fidelity pulsed optomechanical interface based on all-optical presqueezing of non-Gaussian quantum states of light before they enter the optomechanical…
Nonclassical states of levitated macroscopic objects beyond the ground state
Andrey A. Rakhubovsky, Darren W. Moore, Radim Filip
The preparation of nonclassical states of mechanical motion conclusively proves that control over such motion has reached the quantum level. We investigate ways to achieve nonclass…
Estimation of covariance matrix of macroscopic quantum states
László Ruppert, Vladyslav C. Usenko, Radim Filip
For systems analogous to a linear harmonic oscillator, the simplest way to characterize the state is by a covariance matrix containing the symmetrically-ordered moments of operator…
Strategies and trade-offs for controllability and memory time of ultra-high-quality microwave cavities in circuit QED
Iivari Pietikäinen, OndÅej ÄernotÃk, Alec Eickbusch +4
Three-dimensional microwave cavity resonators have been shown to reach lifetimes of the order of a second by maximizing the cavity volume relative to its surface, using better mate…
Quantum non-Gaussian Depth of Single-Photon States
Ivo Straka, Ana PredojeviÄ, Tobias Huber +8
We introduce and experimentally explore the concept of quantum non-Gaussian depth of single-photon states with a positive Wigner function. The depth measures the robustness of a si…
Single-mode Quantum Non-Gaussian Light from Warm Atoms
JaromÃr Mika, Lukáš Lachman, Tomáš Lamich +2
The distributed quantum information processing and hybridization of quantum platforms raises increasing demands on the quality of light-matter interaction and realization of effici…
Pairwise Measurement Induced Synthesis of Quantum Coherence
Mariia Gumberidze, Michal KoláÅ, Radim Filip
Quantum coherent superpositions of states with different energies, i.e., states with coherence with respect to energy basis, are important resource for modern quantum technologies.…
Noiseless conditional teleportation of a single photon
Maria Fuwa, Shunsuke Toba, Shuntaro Takeda +6
We experimentally demonstrate the noiseless teleportation of a single photon by conditioning on quadrature Bell measurement results near the origin in phase space and thereby circu…
Entanglement of coherent states and decoherence
Radim Filip, Jaroslav Rehacek, Miloslav Dusek
A possibility to produce entangled superpositions of strong coherent states is discussed. A recent proposal by Howell and Yazell [Phys. Rev. A 62, 012102 (2000)] of a device which…
Hierarchical Verification of Non-Gaussian Coherence in Bosonic Quantum States
Beate E. Asenbeck, Lukáš Lachman, Ambroise Boyer +4
Non-Gaussianity, a distinctive characteristic of bosonic quantum states, is pivotal in advancing quantum networks, fault-tolerant quantum computing, and high-precision metrology. V…
Optical implementation of the encoding of two qubits to a single qutrit
Lucie Bartuskova, Antonin Cernoch, Radim Filip +3
We have devised an optical scheme for the recently proposed protocol for encoding two qubits into one qutrit. In this protocol, Alice encodes an arbitrary pure product state of two…
Experimental quantum non-Gaussian coincidences of entangled photons
Run-Ze Liu, Yu-Kun Qiao, Lukáš Lachman +7
Quantum non-Gaussianity, a more potent and highly useful form of nonclassicality, excludes all convex mixtures of Gaussian states and Gaussian parametric processes generating them.…
Unconditional preparation of squeezed vacuum from Rabi interactions
Jacob Hastrup, Kimin Park, Radim Filip +1
Squeezed states of harmonic oscillators are a central resource for continuous-variable quantum sensing, computation and communication. Here we propose a method for the generation o…
Noise powered amplification in CV quantum key distribution
Petr Marek, Radim Filip
Amplification plays a key role in classical communication protocols, where it compensates the unavoidable loss of the signal. However, when we enter the quantum domain this approac…
Simple optical measurement of the overlap and fidelity of quantum states: An experiment
Martin Hendrych, Miloslav Dusek, Radim Filip +1
We present the experimental results of measurements of the overlap of both pure and mixed polarization states of photons. The fidelity and purity of mixed states were also measured…
Optimal Phase-Insensitive Force Sensing with Non-Gaussian States
Piotr T. Grochowski, Radim Filip
Quantum metrology enables sensitivity to approach the limits set by fundamental physical laws. Even a single continuous mode offers enhanced precision, with the improvement scaling…
Fermat's Spiral-Based Characterization of Squeezed Nonlinear Motional States of Levitated Nanoparticle
Martin DuchaÅ, Alexandr Jonáš, Radim Filip +4
Controlling the state of motion of optically levitated nanoparticles is crucial for the advancement of precision sensing, fundamental tests of physics, and the development of hybri…
Reliable quantum advantage in quantum battery charging
Davide Rinaldi, Radim Filip, Dario Gerace +1
Quantum batteries represent one of the most promising applications of quantum thermodynamics, whose goal is not only to store energy inside small quantum systems but also to potent…
Multiphoton nonclassical light from clusters of single-photon emitters
Luo Qi, Mathieu Manceau, Andrea Cavanna +8
We study nonclassical features of multiphoton light emitted by clusters of single-photon emitters. As signatures of nonclassicality, we use violation of inequalities for normalized…
Nonlinear Phase Gates as Airy Transforms of the Wigner Function
Darren W. Moore, Radim Filip
Low-order nonlinear phase gates allow the construction of versatile higher-order nonlinearities for bosonic systems and grant access to continuous variable quantum simulations of m…
Continuous-variable Werner state: separability, nonlocality, squeezing and teleportation
Ladislav Mista, Radim Filip, Jaromir Fiurasek
We investigate the separability, nonlocality and squeezing of continuous-variable analogue of the Werner state: a mixture of pure two-mode squeezed vacuum state with local thermal…
Slowing quantum decoherence of oscillators by hybrid processing
Kimin Park, Jacob Hastrup, Jonas Schou Neergaard-Nielsen +3
Quantum information encoded into superposition of coherent states is an illustrative representative of practical applications of macroscopic quantum coherence possessing. However,…
Coherent-state phase concentration by quantum probabilistic amplification
Petr Marek, Radim Filip
We propose novel coherent-state phase concentration by probabilistic measurement-induced ampli- fication. The amplification scheme uses novel architecture, thermal noise addition (…
Nonlinear potential of quantum oscillator induced by single photons
Kimin Park, Petr Marek, Radim Filip
Experimental investigation of the nonlinear dynamics of a quantum oscillator is a long standing goal of quantum physics. We propose a conditional method for inducing an arbitrary n…
Enhanced steady-state coherence via repeated system-bath interactions
Ricardo Román-Ancheyta, Michal KoláÅ, Giacomo Guarnieri +1
The appearance of steady-state coherence (SSC) from system-bath interaction proves that quantum effects can appear without an external drive. Such SSC could become a resource to de…
Brownian motion surviving in the unstable cubic potential and the role of Maxwell's demon
Luca Ornigotti, Artem Ryabov, Viktor Holubec +1
Trajectories of an overdamped particle in a highly unstable potential diverge so rapidly, that the variance of position grows much faster than its mean. Description of the dynamics…
Nonlocality degradation of two-mode squeezed vacuum in absorbing optical fibers
Radim Filip, L. Mista
Transfer of nonlocal two-mode squeezed vacuum state through symmetrical and asymmetrical lossy channel is analysed and we demonstrate that the nonlocality is more robust against lo…
Coherence-based operational nonclassicality criteria
Luca Innocenti, Lukas Lachman, Radim Filip
The nonclassicality of quantum states is a fundamental resource for quantum technologies and quantum information tasks in general. In particular, a pivotal aspect of quantum states…
Experimental Demonstration of Squeezed State Quantum Averaging
Mikael Lassen, Lars Skovgaard Madsen, Metin Sabuncu +2
We propose and experimentally demonstrate a universal quantum averaging process implementing the harmonic mean of quadrature variances. The harmonic mean protocol can be used to ef…
Swap-test interferometry with biased ancilla noise
OndÅej ÄernotÃk, Iivari Pietikäinen, Shruti Puri +2
The Mach--Zehnder interferometer is a powerful device for detecting small phase shifts between two light beams. Simple input states -- such as coherent states or single photons --…
Efficient quantum simulation of nonlinear interactions using SNAP and Rabi gates
Kimin Park, Petr Marek, Radim Filip
Quantum simulations provide means to probe challenging problems within controllable quantum systems. However, implementing or simulating deep-strong nonlinear couplings between bos…
Faithful hierarchy of genuine -photon quantum non-Gaussian light
Lukáš Lachman, Ivo Straka, Josef Hloušek +2
Light is an essential tool for connections between quantum devices and for diagnostic of processes in quantum technology. Both applications deal with advanced nonclassical states b…
Ancilla-Error-Transparent Controlled Beam Splitter Gate
Iivari Pietikäinen, OndÅej ÄernotÃk, Shruti Puri +2
In hybrid circuit QED architectures containing both ancilla qubits and bosonic modes, a controlled beam splitter gate is a powerful resource. It can be used to create (up to a cont…
Indefinite-mean Pareto photon distribution from amplified quantum noise
Mathieu Manceau, Kirill Yu. Spasibko, Gerd Leuchs +2
Extreme events appear in many physics phenomena, whenever the probability distribution has a ''heavy tail'', differing very much from the equilibrium one. Most unusual are the case…
Sufficiency of quantum non-Gaussianity for discrete-variable quantum key distribution over noisy channel
MikoÅaj Lasota, Radim Filip, Vladyslav C. Usenko
Quantum key distribution can be enhanced and extended if nonclassical single-photon states of light are used. We study a connection between the security of quantum key distribution…
Screening of qubit from zero-temperature reservoir
Radim Filip
We suggest an application of dynamical Zeno effect to isolate a qubit in the quantum memory unit against decoherence caused by coupling with the reservoir having zero temperature.…
Experimental demonstration of optimal probabilistic enhancement of quantum coherence
Robert Stárek, Michal MiÄuda, Michal KoláŠ+2
We theoretically and experimentally investigate conditional enhancement of overall coherence of quantum states by probabilistic quantum operations that apply to the input state a q…
Noise resilient quantum interface based on QND interaction
Petr Marek, Radim Filip
We propose a quantum interface protocol based on two quantum-non-demolition interactions (QND) arranged either in sequence or in parallel. Since the QND coupling arises naturally i…
Stabilization of product states and excited-state quantum phase transitions in a coupled qubit-field system
Pavel Stránský, Pavel Cejnar, Radim Filip
We study a system of a single qubit (or a few qubits) interacting with a soft-mode bosonic field. Considering an extended version of the Rabi model with both parity-conserving and…
Beyond Stellar Rank: Control Parameters for Scalable Optical Non-Gaussian State Generation
Fumiya Hanamura, Kan Takase, Hironari Nagayoshi +6
Advanced quantum technologies rely on non-Gaussian states of light, essential for universal quantum computation, fault-tolerant error correction, and quantum sensing. Their practic…
Unitary death of Schrödinger's cat
Pavel Stránský, Pavel Cejnar, Radim Filip
We analyze dynamics of the Rabi model describing interactions of a qubit with a single soft-mode oscillator. We show that the model with a slightly violated parity generates symmet…
Environment-Assisted Decoherence Suppression of Optical Non-Gaussian States
Akihiro Machinaga, Naoki Aritomi, Ryoga Sakurada +10
Optical loss is a common bottleneck in photonic quantum information processing, undermining the quantum advantage over classical approaches. Although several countermeasures, such…
Partial deterministic non-demolition Bell measurement
Ladislav Mišta, Radim Filip
We propose the scheme implementing partial deterministic non-demolition Bell measurement. When it is used in quantum teleportation the information about an unknown input state is o…
Picosecond Schrödinger cat states for ultrafast optical quantum processing
Mamoru Endo, Kan Takase, Takefumi Nomura +12
Non-Gaussian states are essential resources for universal, fault-tolerant optical quantum computing, but their generation rate remains limited by low heralding probabilities and op…
Demonstration of reversible phase-insensitive optical amplifier
Jun-ichi Yoshikawa, Yoshichika Miwa, Radim Filip +1
We experimentally demonstrate phase-insensitive linear optical amplification which preserves the idler at the output. Since our amplification operation is unitary up to small exces…
Nanomechanical State Amplifier Based on Optical Inverted Pendulum
Martin DuchaÅ, Martin Å iler, Petr Jákl +4
A contactless control of mean values and fluctuations of position and velocity of a nanoobject belongs among the key methods needed for ultra-precise nanotechnology and the upcomin…
Optical states with higher stellar rank
Jan ProvaznÃk, Olga Solodovnikova, Radim Filip +1
Quantum non-Gaussian states of traveling light fields are crucial components of quantum information processing protocols; however, their preparation is experimentally challenging.…
Highly asymmetric quantum cloning in arbitrary dimension
Jaromir Fiurasek, Radim Filip, Nicolas J. Cerf
We investigate the universal asymmetric cloning of states in a Hilbert space of arbitrary dimension. We derive the class of optimal and fully asymmetric 1->3 cloners, which produce…
Continuous-variable teleportation of a negative Wigner function
Ladislav Mišta, Radim Filip, Akira Furusawa
Teleportation is a basic primitive for quantum communication and quantum computing. We address the problem of continuous-variable (unconditional and conditional) teleportation of a…
Local quantum coherence with intersource interactions at nonzero temperature
Yehor Hudenko, Michal KoláÅ, Radim Filip +1
Local quantum coherence in a two-level system (TLS) is typically generated via time-dependent driving. However, it can also emerge autonomously from symmetry-breaking interactions…
Preventing side-channel effects in continuous-variable quantum key distribution
Ivan Derkach, Vladyslav C. Usenko, Radim Filip
The role of the side channels in the continuous-variable quantum key distribution is studied. It is shown how the information leakage through a side channel from the trusted sender…
Testing sequential quantum measurements: how can maximal knowledge be extracted?
Eleonora Nagali, Simone Felicetti, Pierre-Louis de Assis +3
The extraction of information from a quantum system unavoidably implies a modification of the measured system itself. It has been demonstrated recently that partial measurements ca…
Reversing Quantum Nondemolition Interaction as Quantum Erasing
Yoshichika Miwa, Jun-ichi Yoshikawa, Ryuji Ukai +2
We reverse a quantum nondemolition (QND) interaction and restore the signal quantum state by measurement and feedforward. This operation corresponds to quantum erasing for continuo…
Criteria for single photon sources with variable nonclassicality threshold
Lukáš Lachman, Radim Filip
Single photon sources are necessary for optical quantum technology. The nonclassicality of emitted single photons manifests itself in diverse experiments and applications. The appl…
Losses resistant verification of quantum non-Gaussian photon statistics
Riccardo Checchinato, Jan-Heinrich Littmann, Lukáš Lachman +5
Quantum non-Gaussian states of light have fundamental properties that are essential for a multitude of applications in quantum technology. However, many of these features are diffi…
Entanglement concentration of continuous variable quantum states
Jaromir Fiurasek, Ladislav Mista, Radim Filip
We propose two probabilistic entanglement concentration schemes for a single copy of two-mode squeezed vacuum state. The first scheme is based on the off-resonant interaction of a…
Continuous-variable quantum passive optical network
Adnan A. E. Hajomer, Ivan Derkach, Radim Filip +3
Building scalable and secure quantum networks with many users has a high application potential but also holds many practical challenges. A significant stride in this pursuit involv…
Deterministic feedforward-based generation of large optical coherent-state superposition
Michele N. Notarnicola, Marcin Jarzyna, Radim Filip
Large optical coherent-state superpositions are essential to advance quantum sensing, quantum repeaters and error-correction codes. We propose a deterministic feedforward protocol…
Pulsed quantum continuous-variable optoelectromechanical transducer
Nikita Vostrosablin, Andrey A. Rakhubovsky, Radim Filip
We propose a setup allowing to entangle two directly non-interacting radiation modes applying four sequential pulsed quantum resonant interactions with a noisy vibrational mode of…
Gaussian error correction of quantum states in a correlated noisy channel
Mikael Lassen, Adriano Berni, Lars S. Madsen +2
Noise is the main obstacle for the realization of fault tolerant quantum information processing and secure communication over long distances. In this work, we propose a communicati…
Squeezed-state quantum key distribution upon imperfect reconciliation
Vladyslav C. Usenko, Radim Filip
We address the security of continuous-variable quantum key distribution with squeezed states upon realistic conditions of noisy and lossy environment and limited reconciliation eff…
Pure single photons from a trapped atom source
Daniel B. Higginbottom, Lukáš SlodiÄka, Gabriel Araneda +4
Single atoms or atom-like emitters are the purest source of on-demand single photons, they are intrinsically incapable of multi-photon emission. To demonstrate this degree of purit…
Photon-phonon-photon transfer in optomechanics
Andrey A. Rakhubovsky, Radim Filip
We consider transfer of a highly nonclassical quantum state through an optomechanical system. That is we investigate a protocol consisting of sequential upload, storage and reading…
Hybrid Rabi interaction with traveling states of light
Kimin Park, Julien Laurat, Radim Filip
Hybrid interactions between light and two-level systems and their nonlinear nature are crucial components of advanced quantum information processing and quantum networks. Rabi inte…
Nonclassical light from a large number of independent single-photon emitters
Lukáš Lachman, Lukáš SlodiÄka, Radim Filip
Nonclassical quantum effects gradually reach domains of physics of large systems previously considered as purely classical. We derive a hierarchy of operational criteria suitable f…
Adapting coherent-state superpositions in noisy channels
Jan ProvaznÃk, Petr Marek, Julien Laurat +1
Quantum non-Gaussian states are crucial for the fundamental understanding of non-linear bosonic systems and simultaneously advanced applications in quantum technologies. In many bo…
Quantum Phase Estimation Beyond the Gaussian Limit
Kimin Park, Tanjung Krisnanda, Yvonne Gao +1
Quantum metrology aims to enhance measurement precision beyond the standard quantum limit (SQL), the benchmark set by classical resources, enabling advances in sensing, imaging, an…
General implementation of arbitrary nonlinear quadrature phase gates
Petr Marek, Radim Filip, Hisashi Ogawa +4
We propose general methodology of deterministic single-mode quantum interaction nonlinearly modifying single quadrature variable of a continuous variable system. The methodology is…
Feasibility of continuous-variable quantum key distribution with noisy coherent states
Vladyslav C. Usenko, Radim Filip
We address security of the quantum key distribution scheme based on the noisy modulation of coherent states and investigate how it is robust against noise in the modulation regardl…
Bimodal non-Gaussian photonic states from a single quantum emitter in a waveguide
Thomas Copie, Ofer Firstenberg, G. P. Teja +2
We investigate the generation of deterministic and heralded non-Gaussian states of light, using a single two-level system coupled to a chiral waveguide. We study the case of a sing…
Thermally-induced qubit coherence in quantum electromechanics
Najmeh Etehadi Abari, Andrey Rakhubovsky, Radim Filip
Quantum coherence, the ability of a quantum system to be in a superposition of orthogonal quantum states, is a distinct feature of the quantum mechanics, thus marking a deviation f…
Synthesizing and multiplexing autonomous quantum coherences
Artur Slobodeniuk, Tomáš Novotný, Radim Filip
Quantum coherence is a crucial prerequisite for quantum technologies. Therefore, the robust generation, as autonomous as possible, of quantum coherence remains the essential proble…
Protecting the quantum interference of cat states by phase-space compression
Xiaozhou Pan, Jonathan Schwinger, Ni-Ni Huang +7
Cat states, with their unique phase-space interference properties, are ideal candidates for understanding fundamental principles of quantum mechanics and performing key quantum inf…
Entanglement with a mode observable via a tunable interaction with a qubit
MaÅgorzata StrzaÅka, Radim Filip, Katarzyna Roszak
We study the possibility of detection of ``spin-boson'' entanglement by qubit only measurements. Such entanglement is impossible to detect by previously proposed schemes that invol…