Uploaded February 2017 | Updated September 2026, 3 weeks ago
What is entanglement really? And why is it that it's a uniquely quantum phenomena?
Homework:
1 Explain why Alice can never send any messages through this set up.
2 This is one to practice working with wavefunctions of several objects. Prove mathematically that it’s impossible to write our state as two separate states for the electron and positron
3 This one is very relevant to quantum computing. If you have just one electron or positron, you only need 2 numbers to describe its state. Now suppose you have n of them. If they are not entangled, how many numbers to you need to describe the state? What about for a general state that is allowed to be entangled?
Bohmian mechanics stuff:
In Bohmian mechanics, you still have superpositions, they just mean something very different. A Bohmian mech particle only has one position, however, it still has a wavefunction that is a superposition of many possibilities. The difference is that the particle has one position but is influenced by other things in it's wavefunction. A particle like this behaves very differently to a classical particle that only has one position and is not at all influenced by it's other possibilities.
What is entanglement really? And why is it that it's a uniquely quantum phenomena?
Homework:
1 Explain why Alice can never send any messages through this set up.
2 This is one to practice working with wavefunctions of several objects. Prove mathematically that it’s impossible to write our state as two separate states for the electron and positron
3 This one is very relevant to quantum computing. If you have just one electron or positron, you only need 2 numbers to describe its state. Now suppose you have n of them. If they are not entangled, how many numbers to you need to describe the state? What about for a general state that is allowed to be entangled?
Bohmian mechanics stuff:
In Bohmian mechanics, you still have superpositions, they just mean something very different. A Bohmian mech particle only has one position, however, it still has a wavefunction that is a superposition of many possibilities. The difference is that the particle has one position but is influenced by other things in it's wavefunction. A particle like this behaves very differently to a classical particle that only has one position and is not at all influenced by it's other possibilities.
