Artificial neural networks can be an important tool to improve the search for admissible string compactifications and characterize them. In this paper we construct the heterotic orbiencoder, a general deep autoencoder to study heterotic orbifold models arising from various Abelian orbifold geometries. Our neural network can be easily trained to successfully encode the large parameter space of many orbifold geometries simultaneously, independently of the statistical dissimilarities of their training features. In particular, we show that our autoencoder is capable of compressing with good accuracy the large parameter space of two promising orbifold geometries in just three parameters. Further, most orbifold models with phenomenologically appealing features appear in bounded regions of this small space. Our results hint towards a possible simplification of the classification of (promising) heterotic orbifold models.
{"title":"An autoencoder for heterotic orbifolds with arbitrary geometry","authors":"Enrique Escalante–Notario, Ignacio Portillo–Castillo, Saúl Ramos–Sánchez","doi":"10.1088/2399-6528/ad246f","DOIUrl":"https://doi.org/10.1088/2399-6528/ad246f","url":null,"abstract":"Artificial neural networks can be an important tool to improve the search for admissible string compactifications and characterize them. In this paper we construct the <monospace>heterotic orbiencoder</monospace>, a general deep autoencoder to study heterotic orbifold models arising from various Abelian orbifold geometries. Our neural network can be easily trained to successfully encode the large parameter space of many orbifold geometries simultaneously, independently of the statistical dissimilarities of their training features. In particular, we show that our autoencoder is capable of compressing with good accuracy the large parameter space of two promising orbifold geometries in just three parameters. Further, most orbifold models with phenomenologically appealing features appear in bounded regions of this small space. Our results hint towards a possible simplification of the classification of (promising) heterotic orbifold models.","PeriodicalId":47089,"journal":{"name":"Journal of Physics Communications","volume":"12 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139767861","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 : 2024-02-08DOI: 10.1088/2399-6528/ad22e5
Yunwei Lu, Sandeep Joshi, Vinh San Dinh, Jens Koch
Gradient Ascent Pulse Engineering (GRAPE) is a popular technique in quantum optimal control, and can be combined with automatic differentiation (AD) to facilitate on-the-fly evaluation of cost-function gradients. We illustrate that the convenience of AD comes at a significant memory cost due to the cumulative storage of a large number of states and propagators. For quantum systems of increasing Hilbert space size, this imposes a significant bottleneck. We revisit the strategy of hard-coding gradients in a scheme that fully avoids propagator storage and significantly reduces memory requirements. Separately, we present improvements to numerical state propagation to enhance runtime performance. We benchmark runtime and memory usage and compare this approach to AD-based implementations, with a focus on pushing towards larger Hilbert space sizes. The results confirm that the AD-free approach facilitates the application of optimal control for large quantum systems which would otherwise be difficult to tackle.
梯度上升脉冲工程（GRAPE）是量子优化控制领域的一种流行技术，它可以与自动微分（AD）相结合，以方便对代价函数梯度进行即时评估。我们的研究表明，自动微分的便利性需要付出巨大的内存代价，因为需要累积存储大量的状态和传播者。对于希尔伯特空间大小不断增大的量子系统来说，这是一个显著的瓶颈。我们重新审视了硬编码梯度的策略，该方案完全避免了传播者的存储，并显著降低了内存需求。另外，我们对数值状态传播进行了改进，以提高运行时性能。我们对运行时间和内存使用情况进行了基准测试，并将这种方法与基于 AD 的实现方法进行了比较，重点是向更大的希尔伯特空间尺寸推进。结果证实，无 AD 方法促进了大型量子系统最优控制的应用，否则很难解决这些问题。
{"title":"Optimal control of large quantum systems: assessing memory and runtime performance of GRAPE","authors":"Yunwei Lu, Sandeep Joshi, Vinh San Dinh, Jens Koch","doi":"10.1088/2399-6528/ad22e5","DOIUrl":"https://doi.org/10.1088/2399-6528/ad22e5","url":null,"abstract":"Gradient Ascent Pulse Engineering (GRAPE) is a popular technique in quantum optimal control, and can be combined with automatic differentiation (AD) to facilitate on-the-fly evaluation of cost-function gradients. We illustrate that the convenience of AD comes at a significant memory cost due to the cumulative storage of a large number of states and propagators. For quantum systems of increasing Hilbert space size, this imposes a significant bottleneck. We revisit the strategy of hard-coding gradients in a scheme that fully avoids propagator storage and significantly reduces memory requirements. Separately, we present improvements to numerical state propagation to enhance runtime performance. We benchmark runtime and memory usage and compare this approach to AD-based implementations, with a focus on pushing towards larger Hilbert space sizes. The results confirm that the AD-free approach facilitates the application of optimal control for large quantum systems which would otherwise be difficult to tackle.","PeriodicalId":47089,"journal":{"name":"Journal of Physics Communications","volume":"15 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139767880","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 : 2024-02-07DOI: 10.1088/2399-6528/ad1f73
Eemeli A Eronen, Anton Vladyka, Florent Gerbon, Christoph J Sahle, Johannes Niskanen
We apply a recently developed technique utilizing machine learning for statistical analysis of computational nitrogen K-edge spectra of aqueous triglycine. This method, the emulator-based component analysis, identifies spectrally relevant structural degrees of freedom from a data set filtering irrelevant ones out. Thus tremendous reduction in the dimensionality of the ill-posed nonlinear inverse problem of spectrum interpretation is achieved. Structural and spectral variation across the sampled phase space is notable. Using these data, we train a neural network to predict the intensities of spectral regions of interest from the structure. These regions are defined by the temperature-difference profile of the simulated spectra, and the analysis yields a structural interpretation for their behavior. Even though the utilized local many-body tensor representation implicitly encodes the secondary structure of the peptide, our approach proves that this information is irrecoverable from the spectra. A hard x-ray Raman scattering experiment confirms the overall sensibility of the simulated spectra, but the predicted temperature-dependent effects therein remain beyond the achieved statistical confidence level.
我们将最近开发的机器学习技术应用于三甘氨酸水溶液的计算氮 K 边光谱的统计分析。这种基于仿真器的成分分析方法能从数据集中识别出与光谱相关的结构自由度，过滤掉不相关的自由度。这样就大大降低了光谱解释的非线性逆问题的维度。整个采样相空间的结构和频谱变化非常明显。利用这些数据，我们训练了一个神经网络，以从结构中预测感兴趣光谱区域的强度。这些区域是由模拟光谱的温差曲线定义的，分析得出了对其行为的结构解释。尽管所利用的局部多体张量表示法隐含了多肽的二级结构，但我们的方法证明了这一信息是无法从光谱中恢复的。硬 X 射线拉曼散射实验证实了模拟光谱的整体灵敏度，但其中预测的温度效应仍然超出了统计置信水平。
{"title":"Information bottleneck in peptide conformation determination by x-ray absorption spectroscopy","authors":"Eemeli A Eronen, Anton Vladyka, Florent Gerbon, Christoph J Sahle, Johannes Niskanen","doi":"10.1088/2399-6528/ad1f73","DOIUrl":"https://doi.org/10.1088/2399-6528/ad1f73","url":null,"abstract":"We apply a recently developed technique utilizing machine learning for statistical analysis of computational nitrogen K-edge spectra of aqueous triglycine. This method, the emulator-based component analysis, identifies spectrally relevant structural degrees of freedom from a data set filtering irrelevant ones out. Thus tremendous reduction in the dimensionality of the ill-posed nonlinear inverse problem of spectrum interpretation is achieved. Structural and spectral variation across the sampled phase space is notable. Using these data, we train a neural network to predict the intensities of spectral regions of interest from the structure. These regions are defined by the temperature-difference profile of the simulated spectra, and the analysis yields a structural interpretation for their behavior. Even though the utilized local many-body tensor representation implicitly encodes the secondary structure of the peptide, our approach proves that this information is irrecoverable from the spectra. A hard x-ray Raman scattering experiment confirms the overall sensibility of the simulated spectra, but the predicted temperature-dependent effects therein remain beyond the achieved statistical confidence level.","PeriodicalId":47089,"journal":{"name":"Journal of Physics Communications","volume":"272 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139767619","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 : 2024-01-25DOI: 10.1088/2399-6528/ad1f74
Kohei Kobayashi
To implement quantum information technologies, carefully designed control for preparing a desired state plays a key role. However, in realistic situation, the actual performance of those methodologies is severely limited by decoherence. Therefore, it is important to evaluate how close we can steer the controlled state to a desired target state under decoherence. In this paper, we provide an upper bound of the distance between the two controlled quantum systems in the presence and absence of decoherence. The bound quantifies the degree of achievement of the control for a given target state under decoherence, and can be straightforwardly calculated without solving any equation. Moreover, the upper bound is applied to derive a theoretical limit of the probability for obtaining the target state under decoherence.
{"title":"Bound on the distance between controlled quantum state and target state under decoherence","authors":"Kohei Kobayashi","doi":"10.1088/2399-6528/ad1f74","DOIUrl":"https://doi.org/10.1088/2399-6528/ad1f74","url":null,"abstract":"To implement quantum information technologies, carefully designed control for preparing a desired state plays a key role. However, in realistic situation, the actual performance of those methodologies is severely limited by decoherence. Therefore, it is important to evaluate how close we can steer the controlled state to a desired target state under decoherence. In this paper, we provide an upper bound of the distance between the two controlled quantum systems in the presence and absence of decoherence. The bound quantifies the degree of achievement of the control for a given target state under decoherence, and can be straightforwardly calculated without solving any equation. Moreover, the upper bound is applied to derive a theoretical limit of the probability for obtaining the target state under decoherence.","PeriodicalId":47089,"journal":{"name":"Journal of Physics Communications","volume":"7 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139773454","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 : 2024-01-23DOI: 10.1088/2399-6528/ad1dc8
T J Volkoff, Michael J Martin
We show that the lowest quantum Cramér-Rao bound achievable in interferometry with a one-axis twisted spin coherent state is saturated by the asymptotic method of moments error of a protocol that uses one call to the one-axis twisting, one call to time-reversed one-axis twisting, and a final total spin measurement (i.e., a twist-untwist protocol). The result is derived by first showing that the metrological phase diagram for one-axis twisting is asymptotically characterized by a single quantum Fisher information value N(N + 1)/2 for all times, then constructing a twist-untwist protocol having a method of moments error that saturates this value. The case of finite-range one-axis twisting is similarly analyzed, and a simple functional form for the metrological phase diagram is found in both the short-range and long-range interaction regimes. Numerical evidence suggests that the finite-range analogues of twist-untwist protocols can exhibit a method of moments error that asymptotically saturates the lowest quantum Cramér-Rao bound achievable in interferometry with finite-range one-axis twisted spin coherent states for all interaction times.
{"title":"Saturating the one-axis twisting quantum Cramér-Rao bound with a total spin readout","authors":"T J Volkoff, Michael J Martin","doi":"10.1088/2399-6528/ad1dc8","DOIUrl":"https://doi.org/10.1088/2399-6528/ad1dc8","url":null,"abstract":"We show that the lowest quantum Cramér-Rao bound achievable in interferometry with a one-axis twisted spin coherent state is saturated by the asymptotic method of moments error of a protocol that uses one call to the one-axis twisting, one call to time-reversed one-axis twisting, and a final total spin measurement (i.e., a twist-untwist protocol). The result is derived by first showing that the metrological phase diagram for one-axis twisting is asymptotically characterized by a single quantum Fisher information value <italic toggle=\"yes\">N</italic>(<italic toggle=\"yes\">N</italic> + 1)/2 for all times, then constructing a twist-untwist protocol having a method of moments error that saturates this value. The case of finite-range one-axis twisting is similarly analyzed, and a simple functional form for the metrological phase diagram is found in both the short-range and long-range interaction regimes. Numerical evidence suggests that the finite-range analogues of twist-untwist protocols can exhibit a method of moments error that asymptotically saturates the lowest quantum Cramér-Rao bound achievable in interferometry with finite-range one-axis twisted spin coherent states for all interaction times.","PeriodicalId":47089,"journal":{"name":"Journal of Physics Communications","volume":"1 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139767879","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 : 2024-01-19DOI: 10.1088/2399-6528/ad1dc7
Tom G Mackay, Akhlesh Lakhtakia
Gyrotropic dielectric materials, being Lorentz non-reciprocal, exhibit scientifically and technologically interesting reflection asymmetries. On numerically characterizing left/right asymmetries in linear reflectances exhibited by a gyrotropic dielectric slab, we found these asymmetries to be highly sensitive to: (i) the constitutive parameters of the gyrotropic dielectric material, (ii) the thickness of the slab, (iii) the direction of incidence, and (iv) the refractive indexes of the isotropic dielectric materials above and below the slab. In particular, left/right reflectance asymmetries increase as (i) dissipation in the gyrotropic dielectric material decreases and (ii) the anti-symmetric component of the relative permittivity dyadic of that material increases. Generally, the cross-polarized left/right reflectance asymmetry is an order of magnitude smaller than the co-polarized left/right reflectance asymmetries.
{"title":"On maximum left/right reflectance asymmetry exhibited by a gyrotropic dielectric slab","authors":"Tom G Mackay, Akhlesh Lakhtakia","doi":"10.1088/2399-6528/ad1dc7","DOIUrl":"https://doi.org/10.1088/2399-6528/ad1dc7","url":null,"abstract":"Gyrotropic dielectric materials, being Lorentz non-reciprocal, exhibit scientifically and technologically interesting reflection asymmetries. On numerically characterizing left/right asymmetries in linear reflectances exhibited by a gyrotropic dielectric slab, we found these asymmetries to be highly sensitive to: (i) the constitutive parameters of the gyrotropic dielectric material, (ii) the thickness of the slab, (iii) the direction of incidence, and (iv) the refractive indexes of the isotropic dielectric materials above and below the slab. In particular, left/right reflectance asymmetries increase as (i) dissipation in the gyrotropic dielectric material decreases and (ii) the anti-symmetric component of the relative permittivity dyadic of that material increases. Generally, the cross-polarized left/right reflectance asymmetry is an order of magnitude smaller than the co-polarized left/right reflectance asymmetries.","PeriodicalId":47089,"journal":{"name":"Journal of Physics Communications","volume":"19 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139508577","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 : 2024-01-05DOI: 10.1088/2399-6528/ad1bb5
D. Szewczyk, A. Krivchikov, A. Jeżowski
The temperature dependencies of the thermal conductivity coefficient, κ(T), in 1-fluoroadamantane were investigated for two different orientationally-disordered states. In the first one, κ(T) exhibits a crystalline character with a typical maximum and two anomalous regions marked at higher temperatures. Here, the low-temperature power-law dependence is reduced due to a relatively large contribution of dislocations and defects in the polycrystalline sample. Above 196 K, there is an anomalous plateau in thermal conductivity resulting from the presence of an intermediate centrosymmetric state. Further, a significant increase in κ occurs above 234 K, resulting from a phase transition to a high-temperature disordered cubic phase. Subsequent cooling of the sample leads to an irreversible transition towards a disordered state resulting in a κ(T) dependence corresponding to an amorphous material behavior. The primary anomaly at 196 K disappears, while the second one associated with the phase transition at 227 K shifts towards lower temperatures. The irreversibility of this transformation is also verified by scanning microscopy images. Thermal conductivity in both phases has an additional contribution of an Arrhenius type in their temperature dependences.
针对两种不同的取向有序状态，研究了 1-氟金刚烷中导热系数 κ(T) 的温度依赖性。在第一种状态中，κ(T) 表现出结晶特性，在较高温度下有一个典型的最大值和两个异常区域。在这里，由于多晶样品中位错和缺陷的贡献相对较大，低温幂律依赖性减弱。在 196 K 以上，由于存在中间向心对称态，热导率出现异常高原。此外，在 234 K 以上，κ 出现了显著的增加，这是由于相变到了高温无序立方相。样品随后的冷却会导致向无序态的不可逆转变，从而产生与无定形材料行为相对应的κ(T)依赖关系。196 K 时的主要异常现象消失了，而与 227 K 时相变相关的第二个异常现象则向更低的温度转移。扫描显微镜图像也验证了这种转变的不可逆性。这两种相的导热性在其温度相关性中都有阿伦尼乌斯类型的额外贡献。
{"title":"Polymorphic states investigations in thermal conductivity of 1-fluoroadamantane","authors":"D. Szewczyk, A. Krivchikov, A. Jeżowski","doi":"10.1088/2399-6528/ad1bb5","DOIUrl":"https://doi.org/10.1088/2399-6528/ad1bb5","url":null,"abstract":"\u0000 The temperature dependencies of the thermal conductivity coefficient, κ(T), in 1-fluoroadamantane were investigated for two different orientationally-disordered states. In the first one, κ(T) exhibits a crystalline character with a typical maximum and two anomalous regions marked at higher temperatures. Here, the low-temperature power-law dependence is reduced due to a relatively large contribution of dislocations and defects in the polycrystalline sample. Above 196 K, there is an anomalous plateau in thermal conductivity resulting from the presence of an intermediate centrosymmetric state. Further, a significant increase in κ occurs above 234 K, resulting from a phase transition to a high-temperature disordered cubic phase. Subsequent cooling of the sample leads to an irreversible transition towards a disordered state resulting in a κ(T) dependence corresponding to an amorphous material behavior. The primary anomaly at 196 K disappears, while the second one associated with the phase transition at 227 K shifts towards lower temperatures. The irreversibility of this transformation is also verified by scanning microscopy images. Thermal conductivity in both phases has an additional contribution of an Arrhenius type in their temperature dependences.","PeriodicalId":47089,"journal":{"name":"Journal of Physics Communications","volume":"80 4","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139383597","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 : 2024-01-05DOI: 10.1088/2399-6528/ad1bb6
Yoseph Abebe Asratie, Tibebe Birhanu Tegegne, Y. Bassie
In this paper, we study the dynamics of particles along a semiconductor layer by imposing a confinement potential assisted by both thermal noise strength D and trap potential φ. By applying a nonhomogeneous cold temperature alongside the uniform background temperature, the system is driven towards a phase transition. When a weak signal is pass across a semiconductor layer, the thermally activated particles become easily hop from one lattice site to another lattice site. We perform a numerical simulation of the trajectory of a particle under a harmonic potential represents a bistable and tristable effective potential as a function of thermal noise. As a result, at an optimal level of noise, the particle synchronizes with a weak periodic signal.
在本文中，我们通过施加由热噪声强度 D 和阱势 φ 辅助的约束势来研究粒子沿半导体层的动力学。当微弱信号穿过半导体层时，热激活粒子很容易从一个晶格位点跳到另一个晶格位点。我们对粒子在代表双稳态和三稳态有效势的谐波势下的轨迹进行了数值模拟，并将其作为热噪声的函数。结果是，在最佳噪声水平下，粒子与微弱的周期信号同步。
{"title":"Thermally activated escape rate and dynamics of a particle under a harmonic potential","authors":"Yoseph Abebe Asratie, Tibebe Birhanu Tegegne, Y. Bassie","doi":"10.1088/2399-6528/ad1bb6","DOIUrl":"https://doi.org/10.1088/2399-6528/ad1bb6","url":null,"abstract":"\u0000 In this paper, we study the dynamics of particles along a semiconductor layer by imposing a confinement potential assisted by both thermal noise strength D and trap potential φ. By applying a nonhomogeneous cold temperature alongside the uniform background temperature, the system is driven towards a phase transition. When a weak signal is pass across a semiconductor layer, the thermally activated particles become easily hop from one lattice site to another lattice site. We perform a numerical simulation of the trajectory of a particle under a harmonic potential represents a bistable and tristable effective potential as a function of thermal noise. As a result, at an optimal level of noise, the particle synchronizes with a weak periodic signal.","PeriodicalId":47089,"journal":{"name":"Journal of Physics Communications","volume":"35 48","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139382607","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 : 2023-12-27DOI: 10.1088/2399-6528/ad1598
Satori Tsuzuki, Eri Itoh, Katsuhiro Nishinari
Recently, we presented a new numerical scheme for vortex lattice formation in a rotating Bose–Einstein condensate (BEC) using smoothed particle hydrodynamics (SPH) with an explicit time-integrating scheme; our SPH scheme could reproduce the vortex lattices and their formation processes in rotating quasi-two-dimensional (2D) BECs trapped in a 2D harmonic potential. In this study, we have successfully demonstrated a simulation of rotating 3D BECs trapped in a 3D harmonic potential forming ‘cigar-shaped’ condensates. We have found that our scheme can reproduce the following typical behaviors of rotating 3D BECs observed in the literature: (i) the characteristic shape of the lattice formed in the cross-section at the origin and its formation process, (ii) the stable existence of vortex lines along the vertical axis after reaching the steady state, (iii) a ‘cookie-cutter’ shape, with a similar lattice shape observed wherever we cut the condensate in a certain range in the vertical direction, (iv) the bending of vortex lines when approaching the inner edges of the condensate, and (v) the formation of vortex lattices by vortices entering from outside the condensate. Therefore, we further validated our scheme by simulating rotating 3D BECs.
{"title":"Three-dimensional analysis of vortex-lattice formation in rotating Bose–Einstein condensates using smoothed-particle hydrodynamics","authors":"Satori Tsuzuki, Eri Itoh, Katsuhiro Nishinari","doi":"10.1088/2399-6528/ad1598","DOIUrl":"https://doi.org/10.1088/2399-6528/ad1598","url":null,"abstract":"Recently, we presented a new numerical scheme for vortex lattice formation in a rotating Bose–Einstein condensate (BEC) using smoothed particle hydrodynamics (SPH) with an explicit time-integrating scheme; our SPH scheme could reproduce the vortex lattices and their formation processes in rotating quasi-two-dimensional (2D) BECs trapped in a 2D harmonic potential. In this study, we have successfully demonstrated a simulation of rotating 3D BECs trapped in a 3D harmonic potential forming ‘cigar-shaped’ condensates. We have found that our scheme can reproduce the following typical behaviors of rotating 3D BECs observed in the literature: (i) the characteristic shape of the lattice formed in the cross-section at the origin and its formation process, (ii) the stable existence of vortex lines along the vertical axis after reaching the steady state, (iii) a ‘cookie-cutter’ shape, with a similar lattice shape observed wherever we cut the condensate in a certain range in the vertical direction, (iv) the bending of vortex lines when approaching the inner edges of the condensate, and (v) the formation of vortex lattices by vortices entering from outside the condensate. Therefore, we further validated our scheme by simulating rotating 3D BECs.","PeriodicalId":47089,"journal":{"name":"Journal of Physics Communications","volume":"189 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139052385","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 : 2023-12-27DOI: 10.1088/2399-6528/ad1597
Yuki Izumida
The characterization of finite-time thermodynamic processes is of crucial importance for extending equilibrium thermodynamics to nonequilibrium thermodynamics. The central issue is to quantify responses of thermodynamic variables and irreversible dissipation associated with non-quasistatic changes of thermodynamic forces applied to the system. In this study, we derive a simple formula that incorporates the non-quasistatic response coefficients with Onsager’s kinetic coefficients, where the Onsager coefficients characterize the relaxation dynamics of fluctuation of extensive thermodynamic variables of semi-macroscopic systems. Moreover, the thermodynamic length and the dissipated availability that quantifies the efficiency of irreversible thermodynamic processes are formulated in terms of the derived non-quasistatic response coefficients. The present results are demonstrated by using an ideal gas model. The present results are, in principle, verifiable through experiments and are thus expected to provide a guiding principle for the nonequilibrium control of macroscopic thermodynamic systems.
{"title":"Non-quasistatic response coefficients and dissipated availability for macroscopic thermodynamic systems","authors":"Yuki Izumida","doi":"10.1088/2399-6528/ad1597","DOIUrl":"https://doi.org/10.1088/2399-6528/ad1597","url":null,"abstract":"The characterization of finite-time thermodynamic processes is of crucial importance for extending equilibrium thermodynamics to nonequilibrium thermodynamics. The central issue is to quantify responses of thermodynamic variables and irreversible dissipation associated with non-quasistatic changes of thermodynamic forces applied to the system. In this study, we derive a simple formula that incorporates the non-quasistatic response coefficients with Onsager’s kinetic coefficients, where the Onsager coefficients characterize the relaxation dynamics of fluctuation of extensive thermodynamic variables of semi-macroscopic systems. Moreover, the thermodynamic length and the dissipated availability that quantifies the efficiency of irreversible thermodynamic processes are formulated in terms of the derived non-quasistatic response coefficients. The present results are demonstrated by using an ideal gas model. The present results are, in principle, verifiable through experiments and are thus expected to provide a guiding principle for the nonequilibrium control of macroscopic thermodynamic systems.","PeriodicalId":47089,"journal":{"name":"Journal of Physics Communications","volume":"28 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139052576","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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