The Secret

The purpose of my thesis, The Secret , is to let a user experience a piece of life and learn how to respect the important secrets of nature by the method of adventure games. In this project I have used an opening animation to bring the user to Africa and several entrances to reach the different games as well as a main room to give the user hints and choices of games. There are five games to test the capabilities of the user: A room which has two doors to try the user\u27s luck and a skeleton to examine the wisdom of user. These five games and the whole concept of the project are based on reality. This is not a game. It is a piece of life, but life is one way. There is no way back. In the opening animation, I wrote these sentences to make the user think about choices in life. Generally, in people\u27s daily lives, they may encounter several problems. Some of them are easy to solve but some are not. Users may need to pay a lot of attention and use knowledge and strength to solve the problems. Sometimes, everything might be useless but luck. In this thesis, I not only use the concepts for solving problems but also give idea of protecting our environment. A great invention or discovery may improve our lives. However, in some different points of view a discovery may change the order or Introduction balance of nature. A statement which was made in the movie Jurassic Park was very interesting and described my concept well. It said, God created dinosaurs, God destroyed dinosaurs, God created human beings, human beings destroyed God and human beings created dinosaurs. In my opinion, scientists or anyone else should not invent or discover something without considering the results. Intelligence and wisdom are always totally different. Introductio

Charge-Density-Wave Transitions of Dirac Fermions Coupled to Phonons

The spontaneous generation of charge-density-wave order in a Dirac fermion system via the natural mechanism of electron-phonon coupling is studied in the framework of the Holstein model on the honeycomb lattice. Using two independent and unbiased quantum Monte Carlo methods, the phase diagram as a function of temperature and coupling strength is determined. It features a quantum critical point as well as a line of thermal critical points. Finite-size scaling appears consistent with fermionic Gross-Neveu-Ising universality for the quantum phase transition, and bosonic Ising universality for the thermal phase transition. The critical temperature has a maximum at intermediate couplings. Our findings motivate experimental efforts to identify or engineer Dirac systems with sufficiently strong and tunable electron-phonon coupling.Comment: 4+3 pages, 4+2 figure

Some canonical basis vectors in the basic Uq (SI n)module

10.1006/jabr.2001.9030Journal of Algebra2482765-779JALG

Symmetry Enforced Self-Learning Monte Carlo Method Applied to the Holstein Model

Self-learning Monte Carlo method (SLMC), using a trained effective model to guide Monte Carlo sampling processes, is a powerful general-purpose numerical method recently introduced to speed up simulations in (quantum) many-body systems. In this work, we further improve the efficiency of SLMC by enforcing physical symmetries on the effective model. We demonstrate its effectiveness in the Holstein Hamiltonian, one of the most fundamental many-body descriptions of electron-phonon coupling. Simulations of the Holstein model are notoriously difficult due to the combination of the typical cubic scaling of fermionic Monte Carlo and the presence of extremely long autocorrelation times. Our method addresses both bottlenecks. This enables simulations on large lattices in the most difficult parameter regions, and evaluation of the critical point for the charge density wave transition at half-filling with high precision. We argue that our work opens a new research area of quantum Monte Carlo (QMC), providing a general procedure to deal with ergodicity in situations involving Hamiltonians with multiple, distinct low energy states.Comment: 4 pages, 3 figures with 2 pages supplemental materia