Pub Date : 2023-11-13DOI: 10.1103/physreva.108.053708
Stepan Balybin, Dariya Salykina, Farid Ya. Khalili
In S. N. Balybin et al. [Phys. Rev. A 106, 013720 (2022)] the scheme of quantum nondemolition measurement of optical quanta that uses a resonantly enhanced Kerr nonlinearity in optical microresonators was analyzed theoretically. It was shown that using modern high-$Q$ microresonators, it is possible to achieve sensitivity several times better than the standard quantum limit. Here we propose and analyze in detail a significantly improved version of that scheme. We show that by using a squeezed quantum state of the probe beam and the antisqueezing (parametric amplification) of this beam at the output of the microresonator, it is possible to reduce the measurement imprecision by about one order of magnitude. The resulting sensitivity allows us to generate and verify multiphoton non-Gaussian quantum states of light, making the scheme considered here interesting for quantum information processing tasks.
在S. N. Balybin等人。从理论上分析了在光学微谐振器中使用共振增强克尔非线性的光学量子非拆除测量方案。结果表明，使用现代高Q微谐振器，可以获得比标准量子极限好几倍的灵敏度。在这里，我们提出并详细分析了该方案的一个显著改进版本。我们表明，通过在微谐振器的输出端使用探针光束的压缩量子态和该光束的抗压缩(参数放大)，可以将测量不精度降低约一个数量级。由此产生的灵敏度使我们能够生成和验证光的多光子非高斯量子态，使这里考虑的方案对量子信息处理任务很有趣。
{"title":"Improving the sensitivity of Kerr quantum nondemolition measurement via squeezed light","authors":"Stepan Balybin, Dariya Salykina, Farid Ya. Khalili","doi":"10.1103/physreva.108.053708","DOIUrl":"https://doi.org/10.1103/physreva.108.053708","url":null,"abstract":"In S. N. Balybin et al. [Phys. Rev. A 106, 013720 (2022)] the scheme of quantum nondemolition measurement of optical quanta that uses a resonantly enhanced Kerr nonlinearity in optical microresonators was analyzed theoretically. It was shown that using modern high-$Q$ microresonators, it is possible to achieve sensitivity several times better than the standard quantum limit. Here we propose and analyze in detail a significantly improved version of that scheme. We show that by using a squeezed quantum state of the probe beam and the antisqueezing (parametric amplification) of this beam at the output of the microresonator, it is possible to reduce the measurement imprecision by about one order of magnitude. The resulting sensitivity allows us to generate and verify multiphoton non-Gaussian quantum states of light, making the scheme considered here interesting for quantum information processing tasks.","PeriodicalId":20121,"journal":{"name":"Physical Review","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136283286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this work, we demonstrate experimentally the efficient generation and tunability of energetic highly elliptical high harmonics in Ar gas, driven by intense two-color counter-rotating laser electric fields. A bichromatic beam tailored by a Mach-Zehnder-Less for Threefold Optical Virginia spiderwort (MAZEL-TOV) apparatus generates high-order harmonic generation (HHG), where the output spectrum of the highly elliptical HHG radiation can be tuned for an energy range of $mathrm{ensuremath{Delta}}Eensuremath{approx}150$ meV in the spectral range of $ensuremath{sim}20$ eV with energy per pulse ${E}^{mathrm{XUV}}ensuremath{approx}400$ nJ at the source. Furthermore, we employ time-dependent density-functional simulations to probe the dependence of the harmonic ellipticity and the strength of the attosecond pulses on the driving-field parameters and demonstrate the robustness of the HHG with the bichromatic field. We show how, by properly tuning the central frequency of the second harmonic, the central frequency of the extreme ultraviolet (XUV) high-harmonic radiation is continuously tuned. The demonstrated energy values largely exceed the output energy from many other laser-driven attosecond sources reported so far and prove to be sufficient for inducing nonlinear processes in an atomic system. We envisage that such tunable energetic highly elliptical HHG spectra can remove the facility restrictions from requirements of few-cycle driving pulses for isolated circular attosecond-pulse generation.
{"title":"Energetic, tunable, highly elliptically polarized higher harmonics generated by intense two-color counter-rotating laser fields","authors":"Emmanouil Vassakis, Saibabu Madas, Leandros Spachis, Theocharis Lamprou, Ioannis Orfanos, Shubhendu Kahaly, Mousumi Upadhyay Kahaly, Dimitris Charalambidis, Emmanouil Skantzakis","doi":"10.1103/physreva.108.053112","DOIUrl":"https://doi.org/10.1103/physreva.108.053112","url":null,"abstract":"In this work, we demonstrate experimentally the efficient generation and tunability of energetic highly elliptical high harmonics in Ar gas, driven by intense two-color counter-rotating laser electric fields. A bichromatic beam tailored by a Mach-Zehnder-Less for Threefold Optical Virginia spiderwort (MAZEL-TOV) apparatus generates high-order harmonic generation (HHG), where the output spectrum of the highly elliptical HHG radiation can be tuned for an energy range of $mathrm{ensuremath{Delta}}Eensuremath{approx}150$ meV in the spectral range of $ensuremath{sim}20$ eV with energy per pulse ${E}^{mathrm{XUV}}ensuremath{approx}400$ nJ at the source. Furthermore, we employ time-dependent density-functional simulations to probe the dependence of the harmonic ellipticity and the strength of the attosecond pulses on the driving-field parameters and demonstrate the robustness of the HHG with the bichromatic field. We show how, by properly tuning the central frequency of the second harmonic, the central frequency of the extreme ultraviolet (XUV) high-harmonic radiation is continuously tuned. The demonstrated energy values largely exceed the output energy from many other laser-driven attosecond sources reported so far and prove to be sufficient for inducing nonlinear processes in an atomic system. We envisage that such tunable energetic highly elliptical HHG spectra can remove the facility restrictions from requirements of few-cycle driving pulses for isolated circular attosecond-pulse generation.","PeriodicalId":20121,"journal":{"name":"Physical Review","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136283804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-13DOI: 10.1103/physreve.108.055205
Haidar Al-Naseri, Gert Brodin
In this paper, a phase-space description of electron-positron pair creation will be applied, based on a Wigner transformation of the Klein-Gordon equation. The resulting theory is similar in many respects to the equations from the Dirac-Heisenberg-Wigner formalism. However, in the former case, all physics related to particle spin is neglected. In the present paper we compare the pair-production rate in vacuum and plasmas, with and without spin effects, in order to evaluate the accuracy and applicability of the spinless approximation. It is found that for modest frequencies of the electromagnetic field the pair production rate of the Klein-Gordon theory is a good approximation to the Dirac theory, provided the matter density is small enough for Pauli blocking to be neglected, and a factor of 2 related to the difference in the vacuum energy density is compensated for.
{"title":"Applicability of the Klein-Gordon equation for pair production in vacuum and plasma","authors":"Haidar Al-Naseri, Gert Brodin","doi":"10.1103/physreve.108.055205","DOIUrl":"https://doi.org/10.1103/physreve.108.055205","url":null,"abstract":"In this paper, a phase-space description of electron-positron pair creation will be applied, based on a Wigner transformation of the Klein-Gordon equation. The resulting theory is similar in many respects to the equations from the Dirac-Heisenberg-Wigner formalism. However, in the former case, all physics related to particle spin is neglected. In the present paper we compare the pair-production rate in vacuum and plasmas, with and without spin effects, in order to evaluate the accuracy and applicability of the spinless approximation. It is found that for modest frequencies of the electromagnetic field the pair production rate of the Klein-Gordon theory is a good approximation to the Dirac theory, provided the matter density is small enough for Pauli blocking to be neglected, and a factor of 2 related to the difference in the vacuum energy density is compensated for.","PeriodicalId":20121,"journal":{"name":"Physical Review","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136283809","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-13DOI: 10.1103/physreve.108.054117
Adriano Valdés Gómez, Francisco J. Sevilla
We analyze fractional Brownian motion and scaled Brownian motion on the two-dimensional sphere ${mathbb{S}}^{2}$. We find that the intrinsic long-time correlations that characterize fractional Brownian motion collude with the specific dynamics (navigation strategies) carried out on the surface giving rise to rich transport properties. We focus our study on two classes of navigation strategies: one induced by a specific set of coordinates chosen for ${mathbb{S}}^{2}$ (we have chosen the spherical ones in the present analysis), for which we find that contrary to what occurs in the absence of such long-time correlations, nonequilibrium stationary distributions are attained. These results resemble those reported in confined flat spaces in one and two dimensions [Guggenberger et al. New J. Phys. 21, 022002 (2019); Vojta et al. Phys. Rev. E 102, 032108 (2020)]; however, in the case analyzed here, there are no boundaries that affect the motion on the sphere. In contrast, when the navigation strategy chosen corresponds to a frame of reference moving with the particle (a Frenet-Serret reference system), then the equilibrium distribution on the sphere is recovered in the long-time limit. For both navigation strategies, the relaxation times toward the stationary distribution depend on the particular value of the Hurst parameter. We also show that on ${mathbb{S}}^{2}$, scaled Brownian motion, distinguished by a time-dependent diffusion coefficient with a power-scaling, is independent of the navigation strategy finding a good agreement between the analytical calculations obtained from the solution of a time-dependent diffusion equation on ${mathbb{S}}^{2}$, and the numerical results obtained from our numerical method to generate ensemble of trajectories.
{"title":"Fractional and scaled Brownian motion on the sphere: The effects of long-time correlations on navigation strategies","authors":"Adriano Valdés Gómez, Francisco J. Sevilla","doi":"10.1103/physreve.108.054117","DOIUrl":"https://doi.org/10.1103/physreve.108.054117","url":null,"abstract":"We analyze fractional Brownian motion and scaled Brownian motion on the two-dimensional sphere ${mathbb{S}}^{2}$. We find that the intrinsic long-time correlations that characterize fractional Brownian motion collude with the specific dynamics (navigation strategies) carried out on the surface giving rise to rich transport properties. We focus our study on two classes of navigation strategies: one induced by a specific set of coordinates chosen for ${mathbb{S}}^{2}$ (we have chosen the spherical ones in the present analysis), for which we find that contrary to what occurs in the absence of such long-time correlations, nonequilibrium stationary distributions are attained. These results resemble those reported in confined flat spaces in one and two dimensions [Guggenberger et al. New J. Phys. 21, 022002 (2019); Vojta et al. Phys. Rev. E 102, 032108 (2020)]; however, in the case analyzed here, there are no boundaries that affect the motion on the sphere. In contrast, when the navigation strategy chosen corresponds to a frame of reference moving with the particle (a Frenet-Serret reference system), then the equilibrium distribution on the sphere is recovered in the long-time limit. For both navigation strategies, the relaxation times toward the stationary distribution depend on the particular value of the Hurst parameter. We also show that on ${mathbb{S}}^{2}$, scaled Brownian motion, distinguished by a time-dependent diffusion coefficient with a power-scaling, is independent of the navigation strategy finding a good agreement between the analytical calculations obtained from the solution of a time-dependent diffusion equation on ${mathbb{S}}^{2}$, and the numerical results obtained from our numerical method to generate ensemble of trajectories.","PeriodicalId":20121,"journal":{"name":"Physical Review","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136283077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-13DOI: 10.1103/physreve.108.055206
Michele Mugnaine, Iberê L. Caldas, José D. Szezech, Ricardo L. Viana
For tokamaks with uniform magnetic shear, Martin and Taylor have proposed a symplectic map which has been used to describe the magnetic field lines at the plasma edge perturbed by an ergodic magnetic limiter. We propose an analytical magnetic field line map, based on the Martin-Taylor map, for a tokamak with arbitrary safety factor profile. With the inclusion of a nonmonotonic profile, we obtain a nontwist map which presents the characteristic properties of degenerate systems, such as the twin islands scenario, shearless curve, and separatrix reconnection. We estimate the width of the islands and describe their changes of shape for large values of the limiter current. From our numerical simulations about the shearless curve, we show that its position and aspect depend on the control parameters.
{"title":"Nontwist field line mapping in a tokamak with ergodic magnetic limiter","authors":"Michele Mugnaine, Iberê L. Caldas, José D. Szezech, Ricardo L. Viana","doi":"10.1103/physreve.108.055206","DOIUrl":"https://doi.org/10.1103/physreve.108.055206","url":null,"abstract":"For tokamaks with uniform magnetic shear, Martin and Taylor have proposed a symplectic map which has been used to describe the magnetic field lines at the plasma edge perturbed by an ergodic magnetic limiter. We propose an analytical magnetic field line map, based on the Martin-Taylor map, for a tokamak with arbitrary safety factor profile. With the inclusion of a nonmonotonic profile, we obtain a nontwist map which presents the characteristic properties of degenerate systems, such as the twin islands scenario, shearless curve, and separatrix reconnection. We estimate the width of the islands and describe their changes of shape for large values of the limiter current. From our numerical simulations about the shearless curve, we show that its position and aspect depend on the control parameters.","PeriodicalId":20121,"journal":{"name":"Physical Review","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136283785","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-13DOI: 10.1103/physreva.108.053310
Yuhang Nie, Jun-Hui Zheng, Tao Yang
The optical lattice plays an important role in the stability and dynamics of quantum droplets. In this article, we investigate the Bogoliubov excitation spectrum of quantum droplets in an optical lattice in the thermodynamic limit. We classify the collective excitations as synchronous modes, Bloch phononic modes, and site-population-imbalanced modes. For synchronous modes, we measure the dipole oscillation frequencies by quench dynamics with a sudden shift of the optical lattice and the breathing frequencies by Floquet dynamics with a periodic change of the lattice depth. Bloch phononic modes are observable from the Landau critical velocity of the droplets. We further discuss the instability induced by site-dependent density fluctuations and calculate the critical filling of atoms where the growth of lattice vacancy breaks down the translational symmetry of the system. This work makes essential steps towards measuring the excitation spectrum and understanding the superfluid nature of quantum droplets in an optical lattice.
{"title":"Spectra and dynamics of quantum droplets in an optical lattice","authors":"Yuhang Nie, Jun-Hui Zheng, Tao Yang","doi":"10.1103/physreva.108.053310","DOIUrl":"https://doi.org/10.1103/physreva.108.053310","url":null,"abstract":"The optical lattice plays an important role in the stability and dynamics of quantum droplets. In this article, we investigate the Bogoliubov excitation spectrum of quantum droplets in an optical lattice in the thermodynamic limit. We classify the collective excitations as synchronous modes, Bloch phononic modes, and site-population-imbalanced modes. For synchronous modes, we measure the dipole oscillation frequencies by quench dynamics with a sudden shift of the optical lattice and the breathing frequencies by Floquet dynamics with a periodic change of the lattice depth. Bloch phononic modes are observable from the Landau critical velocity of the droplets. We further discuss the instability induced by site-dependent density fluctuations and calculate the critical filling of atoms where the growth of lattice vacancy breaks down the translational symmetry of the system. This work makes essential steps towards measuring the excitation spectrum and understanding the superfluid nature of quantum droplets in an optical lattice.","PeriodicalId":20121,"journal":{"name":"Physical Review","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136283969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-13DOI: 10.1103/physreva.108.053506
Samyobrata Mukherjee, Jordi Gomis-Bresco, David Artigas, Lluis Torner
Bound states in the continuum (BICs) exist in a variety of physical systems where they appear as lossless propagating states surrounded by radiating modes. In the case of open systems, they coexist with continuous families of guided states, which may be modes or other BICs, located in different regions of the frequency-momentum parameter space. Here we report anisotropic waveguiding structures where guided modes and BICs protected by symmetry are not possible whatsoever, though an isolated, single interference BIC emerges as a lossless, solitary needle from a sea of radiating states. The needle BIC is the unique possible bound state, which originates from the interplay of the two different radiation channels present in the structure, and remarkably, it exists at a single frequency and a precise propagation direction as a spectrally discrete bound state for any practical range of frequencies.
{"title":"Isolated spectrally discrete bound states in the continuum in an open system","authors":"Samyobrata Mukherjee, Jordi Gomis-Bresco, David Artigas, Lluis Torner","doi":"10.1103/physreva.108.053506","DOIUrl":"https://doi.org/10.1103/physreva.108.053506","url":null,"abstract":"Bound states in the continuum (BICs) exist in a variety of physical systems where they appear as lossless propagating states surrounded by radiating modes. In the case of open systems, they coexist with continuous families of guided states, which may be modes or other BICs, located in different regions of the frequency-momentum parameter space. Here we report anisotropic waveguiding structures where guided modes and BICs protected by symmetry are not possible whatsoever, though an isolated, single interference BIC emerges as a lossless, solitary needle from a sea of radiating states. The needle BIC is the unique possible bound state, which originates from the interplay of the two different radiation channels present in the structure, and remarkably, it exists at a single frequency and a precise propagation direction as a spectrally discrete bound state for any practical range of frequencies.","PeriodicalId":20121,"journal":{"name":"Physical Review","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136283615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-13DOI: 10.1103/physreve.108.054605
Yonglun Jiang, Daniel M. Sussman, Eric R. Weeks
We study particle-scale motion in sheared highly polydisperse amorphous materials, in which the largest particles are as much as ten times the size of the smallest. We find strikingly different behavior from the more commonly studied amorphous systems with low polydispersity. In particular, an analysis of the nonaffine motion of particles reveals qualitative differences between large and small particles: The smaller particles have dramatically more nonaffine motion, which is induced by the presence of the large particles. We characterize how the nonaffine motion changes from the low- to high-polydispersity regimes. We further demonstrate a quantitative way to distinguish between ``large'' and ``small'' particles in systems with broad distributions of particle sizes. A macroscopic consequence of the nonaffine motion is a decrease in the energy dissipation rate for highly polydisperse samples, which is due both to a geometric consequence of the changing jamming conditions for higher polydispersity and to the changing character of nonaffine motion.
{"title":"Effects of polydispersity on the plastic behaviors of dense two-dimensional granular systems under shear","authors":"Yonglun Jiang, Daniel M. Sussman, Eric R. Weeks","doi":"10.1103/physreve.108.054605","DOIUrl":"https://doi.org/10.1103/physreve.108.054605","url":null,"abstract":"We study particle-scale motion in sheared highly polydisperse amorphous materials, in which the largest particles are as much as ten times the size of the smallest. We find strikingly different behavior from the more commonly studied amorphous systems with low polydispersity. In particular, an analysis of the nonaffine motion of particles reveals qualitative differences between large and small particles: The smaller particles have dramatically more nonaffine motion, which is induced by the presence of the large particles. We characterize how the nonaffine motion changes from the low- to high-polydispersity regimes. We further demonstrate a quantitative way to distinguish between ``large'' and ``small'' particles in systems with broad distributions of particle sizes. A macroscopic consequence of the nonaffine motion is a decrease in the energy dissipation rate for highly polydisperse samples, which is due both to a geometric consequence of the changing jamming conditions for higher polydispersity and to the changing character of nonaffine motion.","PeriodicalId":20121,"journal":{"name":"Physical Review","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136283647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Gaussian boson sampling, a computational model that is widely believed to admit quantum supremacy, has already been experimentally demonstrated and is claimed to surpass the classical simulation capabilities of even the most powerful supercomputers today. However, whether the current approach limited by photon loss and noise in such experiments prescribes a scalable path to quantum advantage is an open question. To understand the effect of photon loss on the scalability of Gaussian boson sampling, we analytically derive the asymptotic operator entanglement entropy scaling, which relates to the simulation complexity. As a result, we observe that efficient tensor network simulations are likely possible under the ${N}_{text{out}}ensuremath{propto}sqrt{N}$ scaling of the number of surviving photons ${N}_{text{out}}$ in the number of input photons $N$. We numerically verify this result using a tensor network algorithm with $mathrm{U}(1)$ symmetry, and we overcome previous challenges due to the large local Hilbert-space dimensions in Gaussian boson sampling with hardware acceleration. Additionally, we observe that increasing the photon number through larger squeezing does not increase the entanglement entropy significantly. Finally, we numerically find the bond dimension necessary for fixed accuracy simulations, providing more direct evidence for the complexity of tensor networks.
{"title":"Simulating lossy Gaussian boson sampling with matrix-product operators","authors":"Minzhao Liu, Changhun Oh, Junyu Liu, Liang Jiang, Yuri Alexeev","doi":"10.1103/physreva.108.052604","DOIUrl":"https://doi.org/10.1103/physreva.108.052604","url":null,"abstract":"Gaussian boson sampling, a computational model that is widely believed to admit quantum supremacy, has already been experimentally demonstrated and is claimed to surpass the classical simulation capabilities of even the most powerful supercomputers today. However, whether the current approach limited by photon loss and noise in such experiments prescribes a scalable path to quantum advantage is an open question. To understand the effect of photon loss on the scalability of Gaussian boson sampling, we analytically derive the asymptotic operator entanglement entropy scaling, which relates to the simulation complexity. As a result, we observe that efficient tensor network simulations are likely possible under the ${N}_{text{out}}ensuremath{propto}sqrt{N}$ scaling of the number of surviving photons ${N}_{text{out}}$ in the number of input photons $N$. We numerically verify this result using a tensor network algorithm with $mathrm{U}(1)$ symmetry, and we overcome previous challenges due to the large local Hilbert-space dimensions in Gaussian boson sampling with hardware acceleration. Additionally, we observe that increasing the photon number through larger squeezing does not increase the entanglement entropy significantly. Finally, we numerically find the bond dimension necessary for fixed accuracy simulations, providing more direct evidence for the complexity of tensor networks.","PeriodicalId":20121,"journal":{"name":"Physical Review","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136283095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-13DOI: 10.1103/physreve.108.054405
Mahmood Mazarei, Jan Åström, Jan Westerholm, Mikko Karttunen
Tissue growth kinetics and interface dynamics depend on the properties of the tissue environment and cell-cell interactions. In cellular environments, substrate heterogeneity and geometry arise from a variety factors, such as the structure of the extracellular matrix and nutrient concentration. We used the CellSim3D model, a kinetic cell division simulator, to investigate the growth kinetics and interface roughness dynamics of epithelial tissue growth on heterogeneous substrates with varying topologies. The results show that the presence of quenched disorder has a clear effect on the colony morphology and the roughness scaling of the interface in the moving interface regime. In a medium with quenched disorder, the tissue interface has a smaller interface roughness exponent, $ensuremath{alpha}$, and a larger growth exponent, $ensuremath{beta}$. The scaling exponents also depend on the topology of the substrate and cannot be categorized by well-known universality classes.
{"title":"Effect of substrate heterogeneity and topology on epithelial tissue growth dynamics","authors":"Mahmood Mazarei, Jan Åström, Jan Westerholm, Mikko Karttunen","doi":"10.1103/physreve.108.054405","DOIUrl":"https://doi.org/10.1103/physreve.108.054405","url":null,"abstract":"Tissue growth kinetics and interface dynamics depend on the properties of the tissue environment and cell-cell interactions. In cellular environments, substrate heterogeneity and geometry arise from a variety factors, such as the structure of the extracellular matrix and nutrient concentration. We used the CellSim3D model, a kinetic cell division simulator, to investigate the growth kinetics and interface roughness dynamics of epithelial tissue growth on heterogeneous substrates with varying topologies. The results show that the presence of quenched disorder has a clear effect on the colony morphology and the roughness scaling of the interface in the moving interface regime. In a medium with quenched disorder, the tissue interface has a smaller interface roughness exponent, $ensuremath{alpha}$, and a larger growth exponent, $ensuremath{beta}$. The scaling exponents also depend on the topology of the substrate and cannot be categorized by well-known universality classes.","PeriodicalId":20121,"journal":{"name":"Physical Review","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136283825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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