Physics
The essential topics here will give you a strong foundation to understand the 'quantum' in QC.
Bra-ket notation, electrostatics and electrodynamics, hamiltonians, and many-particle systems are some of
the topics relevant to QC that will be covered by these. The supplementary topics are
where you can specialize in a particular experimental realization of QC
such as superconducting QC, trapped ion QC, photonic QC etc.
Essential topics:
Quantum Mechanics
Electricity and Magnetism
Classical Mechanics
Statistical Mechanics
Computational Physics
Supplementary topics:
Solid State Physics (for superconducting based QC)
Atomic & Molecular Physics (for trapped ion based QC)
Photonics & Optics (for photonic based QC)
Computer Science
The essential topics here will give you a strong foundation to understand the 'computing' in QC.
Asymptotic notation, algorithm design, data structures, and complexity classes are some of
the topics relevant to QC that will be covered by these. The supplementary topics are where you can either specialize in a
particular application of QC or the computational theory behind it.
Essential topics:
Object-oriented Programming with Data Structures
Design & Analysis of Algorithms
Theory of Computation
Discrete Mathematics
Supplementary topics:
Machine Learning
Classical & Quantum Complexity Theory
Computer Architecture
Cryptography
Mathematics
The essential topics here will give you a strong foundation to understand the math behind QC.
Integration, matrix diagonalization, probability distributions, and group theory are some of
the topics relevant to QC that will be covered by these. The supplementary topics are where you can learn
math specialized towards things like quantum error correcting codes, quantum cryptography, or a particular physical realization
of a quantum computer such as superconducting QC, trapped ion QC, photonic QC etc.
I will mainly list those relevant to photonics as that is what I work with.
Essential topics:
Linear Algebra
Multi-variable Calculus
Probability Theory
Complex Analysis
Abstract Algebra
Discrete Mathematics
Ordinary and Partial Differential Equations
Supplementary topics:
Coding Theory
Cryptography
Group and Representation Theory
Abstract Geometry
Topology
Real Analysis