物質には固体、液体、気体以外に、液晶、磁石、ガラス、超伝導体などさまざまな状態があり、新たなものも発見され続けています。物質が構成される原子から、どのように物質の状態とその明確な物理的性質が現れるかを理解しようとするのが物性物理学です。脳が意識を持つ一方でひとつの神経細胞はそうではないといった創発現象は、物性物理学の中心であると同時に、生物学、計算機科学、社会学など多くの分野に豊かなつながりをもたらしています。シリコンチップや液晶ディスプレイ、磁気メモリに使われている材料は私たちの生活を大きく変えました。それらを理解しようとすることは、複雑な秩序やシステムに対する私たちの考え方を一変させるでしょう。
 

• Provides a modern introduction to a major field of physics that underpins silicon chips and liquid crystals, and explores deep questions about the nature and behaviour of matter
• Focuses on introducing the fundamental concepts of condensed matter physics and uses concrete examples to illustrate these
• Highlights the role of emergence (the whole is greater than the sum of the parts) in condensed matter physics
• Shows how condensed matter physics links to other fields of physics and to other sciences

   
There are many more states of matter than just solid, liquid, and gas. Examples include liquid crystal, magnet, glass, and superconductor. New states are continually, and unexpectedly, being discovered. Some states, such as superconductor, can act like Schrödinger's cat and exhibit the weirdness normally associated with the quantum theory of atoms, photons, and electrons. Condensed matter physics seeks to understand how states of matter and their distinct physical properties emerge from the atoms of which a material is composed.
      
A system of many interacting parts can have properties that the parts do not have. Water is wet, but a single water molecule is not. Your brain is conscious, but a single neuron is not. Such emergent phenomena are central to condensed matter physics and also occur in many fields, from biology to computer science to sociology, leading to rich intellectual connections. When do quantitative differences become qualitative differences? Can simple models describe rich and complex behaviour? What is the relationship between the particular and the universal? How is the abstract related to the concrete? Condensed matter physics is all about these big questions.
        
The materials in silicon chips, liquid crystal displays, and magnetic computer memories, may have transformed society, but understanding them has transformed how we think about complex systems.