Two qubit state: Separable vs Entangled vs Bell states

Suppose we have a composite quantum system made up of two qubits, how do we describe its state? In this video, we discuss how to describe such composite system in terms of its tensor product. We define the concept of separable versus entangled states in such composite two qubit system. We also explain how one can define a reduced density matrix for the subsystems, and from which a measure for the degree of entanglement can be established. We introduced the Bell states, which are two qubit states with maximum entanglement. Let’s begin.

Technical Content: Johnathas Forte, Tony Low
Video Production: Katie Low, Tony Low

[MiguelBacaoco]

Thanks for the really nice and concise video on composite quantum systems. What book do you recommend that contains these topics? Thanks!

[JonahBernard]

Can you please explain the intuition behind the separability condition formula (or even make a video about it)?

[JoseDanielFSX]

Hello, thank you for your video, I'm currently writing my thesis on this topic. I'd like to propose a question, is there any way to find a generalization of the separability condition for n dimensions?

[dfhk]

for calculating the average value of an observable when can we use the density matrix and when can we use the reduced density matrix

[stephengibert]

Prof Nano is perfect for me because I have a nano brain.