Some Remarks on Quantum Coherence

TL;DR

This paper explores the concept of quantum coherence, providing a definition, discussing its implications, and highlighting its relevance in cosmology and quantum computation, especially regarding environmental interactions.

Contribution

It offers a clear definition of quantum coherence and discusses its implications across different fields, emphasizing the role of environmental interactions.

Findings

Defined quantum coherence and explored its implications.

Highlighted potential for discovering new coherence effects.

Discussed environmental impact on quantum coherence.

Abstract

There are many striking phenomena which are attributed to ``quantum coherence''. It is natural to wonder if there are new quantum coherence effects waiting to be discovered which could lead to interesting results and perhaps even practical applications. A useful starting point for such discussions is a definition of ``quantum coherence''. In this article I give a definition of quantum coherence and use a number of illustrations to explore the implications of this definition. I point to topics of current interest in the fields of cosmology and quantum computation where questions of quantum coherence arise, and I emphasize the impact that interactions with the environment can have on quantum coherence.