Spin Fluctuations and Entanglement
I will compare the effects of quantum and thermal fluctuations
in a spin chain by calculating the probability distribution for spin
fluctuations in a segment. The calculation will use the concept of an
"entanglement Hamiltonian." The entanglement Hamiltonian can be used
to identify topological phases, but I will show that it is helpful for longwavelength
correlations as well as topological ones. The entanglement
Hamiltonian is an imaginary system that describes the correlations of the
ground state. It cannot be measured directly, but it is related to the
statistics of the fluctuations, so measuring the spin fluctuations of the
atoms on the sites of an optical lattice is an indirect way of measuring the
Subscribe to A Quantum Bit
Quantum physics began with revolutionary discoveries in the early twentieth century and continues to be central in today’s physics research. Learn about quantum physics, bit by bit. From definitions to the latest research, this is your portal. Subscribe to receive regular emails from the quantum world. Previous Issues...
Sign Up Now
Sign up to receive A Quantum Bit in your email!