Physics0.01 : Object-Oriented Programming for Exact Diagonalization

TL;DR

This paper introduces a C# library for exact diagonalization in physics, emphasizing object-oriented design with clear terminology, demonstrated through calculating quantum dot ground state energies.

Contribution

It presents a novel object-oriented library for exact diagonalization using C#, with a focus on clear, textbook-like terminology and modular code structure.

Findings

Successful calculation of quantum dot ground state energy

Demonstration of triplet-singlet transition in quantum dots

Clear separation of model-independent and dependent code

Abstract

A new system of library code is proposed and initiated. It is emphasized that the same terminologies as we find in our textbooks should be used for class names in the library code. The language C# invented by Microsoft is adopted in this project. Several rules of thumb are suggested in order to obtain easy-readable coherent codes. As a first step, we present the library code for exact diagonalization in physics. When we build codes, we clearly distinguish between model independent and dependent parts, and we use familiar terminologies like {\sf Hamiltonian}, {\sf HilbertSpace}, {\sf GroundState}, {\it etc} as class names. As an explicit example, we calculate ground state energy of a quantum dot, showing the triplet-singlet transition.