Electrons Entangled with Nucleus?

[LarryS]

Consider the simplest of all possible atoms: A hydrogen atom with only a proton as its nucleus.

According to QFT, the electron is constantly exchanging photons with the proton.

So, are the electron and proton entangled?

Thanks in advance.

 

[Dickfore]

Entanglement does not mean exchanging virtual particles. It means several identical, and indistinguishable particles to be found in a common multi-particle state that cannot be factor in single-particle states. The nucleus, and the electron are intrinsically different. Therefore, one cannot speak of entanglement in the usual sense, as used in Quantum Mechanics.

 

[LarryS]

Entanglement does not mean exchanging virtual particles. It means several identical, and indistinguishable particles to be found in a common multi-particle state that cannot be factor in single-particle states. The nucleus, and the electron are intrinsically different. Therefore, one cannot speak of entanglement in the usual sense, as used in Quantum Mechanics.

Virtual particles not causing entanglement makes sense. Thanks.

But, from what I have read (Susskind, Penrose), entanglement between different types of parties can exist. Entanglement that occurs between identical particles is just one type of entanglement.

 

[Bill_K]

Referframe, you're correct. Given an atom in a specific state of total angular momentum, it will be in a superposition of states with specific electron spin and nuclear spin. Although the particles are not identical, their spins are entangled. Subsequently if the nuclear spin is measured, e.g. by a gamma decay and measurement of the gamma spin, the electron spin will be determined.

 

[DrChinese]

Virtual particles not causing entanglement makes sense. Thanks.

But, from what I have read (Susskind, Penrose), entanglement between different types of parties can exist. Entanglement that occurs between identical particles is just one type of entanglement.

That is correct. Consider as well the 3 quarks that make up a proton or neutron. They are entangled too. For example: color, spin...