Unfortunately, I couldn't find any specific publications that exclusively cover the quantum mechanics and applications section of the UPSC Physics optional. However, there are several books and study materials that can be helpful in preparing for this section. Here are some popular resources:

1. "Quantum Mechanics Concepts and Applications" by Nouredine Zettili: This book provides a comprehensive introduction to quantum mechanics, including its mathematical foundations and various applications. It covers topics such as wave-particle duality, quantum mechanics of systems with spin, quantum mechanics of many-particle systems, and perturbation theory.

2. "Quantum Mechanics: Concepts and Applications" by Ajoy Ghatak and S. Lokanathan: This book offers a clear and concise explanation of quantum mechanics concepts, including wave-particle duality, wave equations, and operators. It also discusses applications of quantum mechanics in different areas such as atomic, molecular, and solid-state physics.

3. "Principles of Quantum Mechanics" by R. Shankar: This book provides a thorough introduction to the principles of quantum mechanics, covering topics such as wave mechanics, matrix mechanics, and quantum dynamics. It also includes discussions on various applications of quantum mechanics, including quantum statistics and quantum information theory.

4. "Quantum Mechanics: Concepts and Applications" by Rajasekar S: This book offers a comprehensive overview of quantum mechanics, covering topics such as wave-particle duality, Schrödinger equation, and quantum dynamics. It also includes chapters on quantum mechanics of angular momentum, perturbation theory, and quantum statistics.

5. "Quantum Mechanics and Path Integrals" by Richard P. Feynman and Albert R. Hibbs: This book provides a unique perspective on quantum mechanics through the use of path integrals. It covers topics such as Feynman's path integral formulation, quantum dynamics, and applications in quantum electrodynamics.

It is important to note that while these resources can be helpful in understanding the concepts and applications of quantum mechanics, it is also advisable to refer to the syllabus and previous years' question papers of the UPSC Physics optional to get a better idea of the specific topics and areas that need to be covered. Additionally, referring to other standard textbooks on quantum mechanics such as "Principles of Quantum Mechanics" by P.A.M. Dirac or "Modern Quantum Mechanics" by J.J. Sakurai can also be beneficial.