What is condensed matter physics?
Condensed matter physics is a discipline that studies the structure and dynamic process of condensed matter composed of a large number of particles (atoms, molecules, ions and electrons) and its relationship with macroscopic physical properties from a microscopic point of view. Condensed matter physics is an outward extension based on solid state physics.
The research object of condensed matter physics
The research objects of condensed matter physics include not only solid substances such as crystals, amorphous crystals and quasicrystals, but also dense gases, liquids and various intermediate condensed phases between liquids and solids, such as liquid helium, liquid crystals, molten salts, liquid metals, electrolytes, glasses and gels. After half a century's development, condensed matter physics has made great progress, and the research object is expanding and more complicated. On the one hand, the research of various branches of traditional solid state physics, such as metal physics, semiconductor physics, magnetism, low temperature physics, dielectric physics and so on, is more in-depth and the links between branches are closer; On the other hand, many new branches are emerging, such as strongly correlated electronic system physics, disordered system physics, quasicrystal physics, mesoscopic physics and cluster physics. Therefore, condensed matter physics has become one of the most important branches of physics at present, and the number of people engaged in condensed matter research is second to none among physicists, and the number of papers published every year ranks first among all branches of physics. It has effectively promoted the development of interdisciplinary subjects such as chemistry, physics, biophysics and geophysics.
As we all know, the complex and diverse forms of matter are basically divided into three categories: gas, liquid and solid. Among these three states, condensed matter physics accounts for two, which determines that every step of this subject is closely related to our human life. From traditional metals and alloys to new semiconductor and superconducting materials, from glass and ceramics to various polymers and composite materials, from various optical crystals to various liquid crystal materials and so on. The acoustic, optical, electrical, magnetic and thermal properties of all these materials are based on the study of condensed matter physics. The study of condensed matter physics also directly provides the foundation for many high technologies themselves. Nowadays, microelectronics, laser technology, optoelectronics and optical fiber communication technology are closely related to the research and development of condensed matter physics.
However, condensed matter physics regards everything as an atom and studies all kinds of condensed matter on the basis of quantum mechanics, which is a very ambitious move. It should be said that it comes from the study of solid crystalline solid and liquid quantum liquid. In the long-term study of these two special States, people have accumulated some experience and established some confidence, and gradually extended some existing methods to the study of amorphous, liquid crystal and even liquid state, thus greatly broadening their horizons and gradually forming condensed matter physics.
Today, the field of vision of condensed matter physics continues to expand. However, as the origin of two condensed states, namely crystalline solid and quantum liquid, it is still the main research object today, with more and more contents and more in-depth considerations. After all, we face the same nature, and many phenomena and laws are universal. It is through the in-depth study of a series of special States that people gradually understand and master those universal laws.
What's the difference between material physics and condensed matter physics?
Materials physics is a new interdisciplinary subject based on the principles of physics, which provides the structure, characteristics and performance of materials, and mainly focuses on the exploration of new functional materials such as new energy and new information.
Condensed matter physics is a subject that studies the physical properties and microstructure of condensed matter and their relationship, that is, by studying the motion forms and laws of electrons, ions, atoms and molecules that make up condensed matter, we can understand its physical properties. Therefore, compared with condensed matter physics, material physics is more practical in life.