近畿大学理工学部物理学コースの量子制御研究室、量子多体物理学研究室、物性理論研究室が合同で運営する量子物理学および量子技術に関するセミナーです。学期中は基本的に毎週水曜日15:00-16:30に開催しています。

今後の予定

2021年度


日時:2021年4月21日9:00-

教室:Zoomによるオンライン配信

発表者:飯ヶ谷 清仁(California Institute of Technology)

題目:Neural principles of subjective value construction

概要:It is an open question how humans construct the subjective value of complex objects (stimuli), such as artistic paintings or photographs. While great progress has been made toward understanding how the brain adjusts the value of objects through reinforcement-learning, little is known about how the value arises in the brain in the first place. Here, we propose and provide evidence that the brain constructs the value of a novel stimulus by extracting and assembling common features. Notably, because those features are shared across a broad range of stimuli, we show that simple linear regression in the feature space can work as a single neural mechanism to construct the value across stimulus domains. In large-scale behavioral experiments with human participants, we show that a simple model of feature abstraction and linear summation can predict the subjective value of paintings, photographs, as well as shopping items whose values change according to different goals. The model shows a remarkable generalization across stimulus types and participants, e.g. when trained on liking ratings for photographs, the model successfully predicts a completely different set of art painting ratings. Also, we show that these general features emerge through image recognition training in a deep convolutional neural network, without explicit training on the features, suggesting that features relevant for value computation arise through natural experience. Furthermore, using fMRI, we found evidence that the brain actually performs value computation hierarchically by transforming low-level visual features into high-level abstract features which in turn are transformed into valuation. We conclude the feature-based value computation is a general neural principle enabling us to make flexible and reliable value computations for a wide range of complex stimuli.

公式には近畿大学大学院総合理工学研究科学際セミナーとして開催。


日時:2021年5月12日10:45-

教室:31号館8F 31-808教室 + Zoomによるオンライン配信

発表者:後藤 慎平(量子多体)

題目:TBA

概要:TBA


日時:2021年5月19日10:45-

教室:31号館8F 31-808教室 + Zoomによるオンライン配信

発表者:久木田 真吾(量子制御)

題目:TBA

概要:TBA


日時:2021年5月26日10:45-

教室:31号館8F 31-808教室 + Zoomによるオンライン配信

発表者:近藤 康(量子制御)

題目:TBA

概要:TBA


日時:2021年6月2日10:45-

教室:31号館8F 31-808教室 + Zoomによるオンライン配信

発表者:金子 隆威(量子多体)

題目:TBA

概要:TBA


日時:2021年6月9日10:45-

教室:31号館8F 31-808教室 + Zoomによるオンライン配信

発表者:Mikkelsen, Mathias(量子多体)

題目:TBA

概要:TBA


日時:2021年6月16日10:45-

教室:31号館8F 31-808教室 + Zoomによるオンライン配信

発表者:段下 一平(量子多体)

題目:TBA

概要:TBA


日時:2021年6月23日10:45-

教室:31号館8F 31-808教室 + Zoomによるオンライン配信

発表者:鏡原 大地(量子多体)

題目:TBA

概要:TBA


日時:2021年6月30日10:45-

教室:31号館8F 31-808教室 + Zoomによるオンライン配信

発表者:笠松 健一(物性理論)

題目:TBA

概要:TBA

過去の講演

2021年度

日時:2021年4月14日10:45-

教室:31号館8F 31-808教室 + Zoomによるオンライン配信

発表者:小久保 治哉(物性理論)

題目:Wave pattern formation of quantum Kelvin-Helmholtz instability in binary superfluids

概要:Kelvin-Helmholtz instability (KHI) is an instability of an interface in phase separated two component fluids with relative velocity. Sinusoidal growth appears at the interface over time, forming a large spiral structure by this instability [1]. A Weber number is a dimensionless number defined by the ratio of the inertial force of the fluid to the surface tension. This number can characterize the dynamics of interface growth driven by the KHI [2].

An interface in a superfluid causes a phenomenon similar to KHI, and in fact, it has been studied experimentally in a superfluid He [3]. In a Bose-Einstein condensate (BEC) of ultra cold atoms, the dissipation mechanism can be approximately ignored, and thus an instability phenomenon similar to the dynamic instability in the ideal classical fluid can be seen. The KHI in BECs has been studied theoretically [4].

In this talk, we will show that the pattern forming dynamics caused by the KHI can be classified by the Weber number defined for two component superfluids with a relative velocity. This Weber number(We) can be written the ratio an interface thickness to the wave length of the most unstable mode of the KHI in a superfluid. On We << 1, an interface forms finger pattern. On We >> 1, an interface forms either sealskin pattern or zipper pattern depending on the interface thickness.

[1]Hydrokinetic solutions and observations. Kelvin, Load (William Thomson), Phil. Mag. (4), vol.42, 362-377.
[2]Simulation Of Viscous Stabilization Of Kelvin- Helmholtz Instability. AT Dinh, et al., Advances in Fluid Mechanics III
[3]Shear Flow and Kelvin-Helmholtz Instability in Superfluids R. Blaauwgeers, et al. PRL 89, 155301
[4]Quantum Kelvin-Helmholtz instability in phase-separated two-component Bose-Einstein condensates Hiromitsu Takeuchi, et al. PRB 81, 094517


2020年度

2019年度