Quantum Fluctuations in Spin Chains

TYPECondensed Matter Seminar
Speaker:Prof. Ari Turner
Affiliation:Johns Hopkins
Location:Lidow Nathan Rosen (300)
Abstract:Quantum systems might not become ordered at zero temperature, due to quantum fluctuations.
I will talk about how the quantum fluctuations are different than classical fluctuations.

To understand the quantum fluctuations, one can map them to finite temperature fluctuations of an imaginary system, called the entanglement Hamiltonian. This "Hamiltonian" cannot be measured directly, but it can be related to the surface states of topological phases and to the statistics of fluctuations.

I'll calculate the probability distribution for spin fluctuations in a segment
of a 1-D quantum-disordered system by mapping it to thermal fluctuations of the entanglement Hamiltonian. This mapping shows that measuring the spin fluctuations of the atoms on the sites of an optical lattice is an indirect way of measuring the entanglement Hamiltonian.