# Application of Virtual Reality in Learning Quantum Mechanics
## 1 Introduction  
Quantum mechanics is a physical theory that describes the behavior of microscopic matter [1], and it is essential for understanding all fundamental forces other than gravity. Its appearance has caused revolutionary changes in physics, so quantum mechanics and relativity are considered the two pillars of modern physics. In 1687, [PERSON], a famous physicist, mathematician, and astronomer, used induction and deduction to explain the physical and mechanical principles of the conservation of momentum and angular momentum. The three laws of motion and the law of universal gravitation laid the foundation for classical physics and established a firm foundation [2]. Before the emergence of quantum theory, it was generally believed that Newtonian mechanics was sufficient to explain the motion of all objects. With the continuous improvement in science and technology, physicists have gradually discovered that although the theory of classical mechanics can accurately describe the motion of objects, it must meet two prerequisites: the size of the object is much larger than atoms, and the speed of the object is much less than the light speed. When humans begin to explore the microscopic world, the properties of matter automatically exhibit quantum effects, and the wisdom of classical physics was unable to explain many physical phenomena. In order to solve these problems, quantum mechanics and relativity were developed in the early 20 th century and greatly changed our understanding of nature [3]. In 1900, German physicist [PERSON] introduced the concept of energy quanta to overcome the difficulty in classical physics in explaining the law of black body radiation,which laid the foundation for quantum theory [4]. After that, [PERSON] analyzed the photoelectric effect and proposed the light quantum hypothesis in 1905 [5]. He believed that electromagnetic radiation is composed of photons discretely distributed in space and thus solved the problem of having difficulty explaining optical phenomena with the classical theory of electromagnetic waves. In 1913, [PERSON] successfully explained the spectrum of hydrogen atoms by using the concept of quantization based on [PERSON]'s nuclear model [6]. In [PERSON]'s hydrogen atom model, electrons move as standing waves, and the length of their orbits must be an integer multiple of the wavelength to form a stable standing wave around the nucleus. The period from 1900 to 1913 can be called the initial stage in the development of quantum theory. Over the next few years, many physicists worked hard to develop quantum theory but encountered great difficulties. In order to solve these fundamental problems, they could only wait for the emergence of a new idea, that is wave-particle duality. According to quantum theory, every quantum entity may be described as a wave or a particle. [PERSON] proposed this property in 1905 and 1916 [7], and it was verified by the photoelectric effect experiment of [PERSON] and the X-ray scattering experiment of [PERSON], but the matter wave theory was not confirmed until it was proposed by [PERSON] in 1923 [8]. In the following years, scientists' findings such as [PERSON]'s uncertainty principle, [PERSON]'s wave equation, and [PERSON]'s wave function by probability [9] finally formed a complete theory of quantum mechanics, and all together with [PERSON]'s theory of relativity became the two theoretical foundations of modern physics [10]. In 1928, [PERSON] applied the theory of relativity to quantum mechanics with the contribution of [PERSON], [PERSON], and other scientists. After that, quantum electrodynamics was thus formed as the basis to develop the quantum field theory of electrodynamics based on relativity. It studies the interaction between electromagnetic fields and charged particles and is mainly used to explain the phenomena caused by the interaction of all charged particles through the exchange of photons [11]. Quantum mechanics is the basic theory used to describe the physical properties of nature in the microscopic world.