This book presents and discusses current research in the field of quantum physics. Chapter One reviews the impact of quantum field theory on the feasibility of local causal models of quantum theory. Chapter Two examines the uncertainty principle and minimal length at all energy scales and some of its implications. Chapter Three shows that the study of graphene physics is a versatile problem, from which we can extract important lessons on condensed matter and quantum field theory, ranging from the concept of emergent phenomenology to relativistic quantum fields and Feynman propagators.