Sangup PARK*

Department of Nano Advanced Materials Engineering, JeonJu University, Jeonju 55069, Korea

We construct the physical stock market and an indicator for the closing price from the economic function of the stock price flow. The thermodynamical potential of the Bose-Einstein partition function of nonlocal free particles near zero temperature shows that a society having motive serves as the entropy of the potential and states with negative internal energy and participators serve as the number of particles. By connecting the economic function and the internal energy, we find a thermal-state space similar to the Hilbert space of information on the stock price flow. The Hilbert space has a quantum phase operator and a finite number of quantum phase states. Thus, we define it as the physical stock market. The Berry phase of the states is introduced, and the correlation function between the Berry phase and the returns of the stock price is calculated. Thus, the correlation with the current return shows a stable value of about 85% after 5 minutes. The correlation with the closing return shows about 60% and 70% agreement after 50 and 100 minutes from the opening. Thus, we see the Berry phase as a good predictor of the closing price.

New Phys.: Sae Mulli 2019; 69: 1288-1294

Dohyeong JANG, Dongryul JEON*

Department of Physics Education, Seoul National University, Seoul 08826, Korea

Light diffraction requires submillimeter-size apertures. The usual method to make diffraction apertures of various shapes is a photography technique for reducing the size of the aperture pattern to a submillimeter level. Because this method requires much effort and time, we here show that a spatial light modulator (SLM) can serve as a ready-to-use diffraction aperture. Because the pixels of the liquid crystal panel of a SLM can be controlled individually by a simple software to either pass or block the light, one can realize a diffraction aperture of any shape. We tested circular square and hexagonal apertures using a SLM and confirmed that the diffraction patterns agreed with the simulated patterns. The diffraction pattern produced by using a double helix aperture, which is a more complicated shape, looked similar to the X-ray diffraction pattern of DNA. Diffraction is an important tool for structural analysis, but determining the real structure from a diffraction pattern is not easy. For that reason, we suggest that SLM apertures may be a handy and practical tool for teaching and learning about diffraction theory.

New Phys.: Sae Mulli 2019; 69: 1257-1262