Class of variational Ansätze for the spin-incoherent ground state of a Luttinger liquid coupled to a spin bath
Feiguin, Adrian E.
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Citation (published version)Mohammad Soltanieh-ha, Adrian E Feiguin. "Class of variational Ansätze for the spin-incoherent ground state of a Luttinger liquid coupled to a spin bath." Physical Review B, Volume 86, Issue 20, https://doi.org/10.1103/physrevb.86.205120
Interacting one-dimensional electron systems are generally referred to as “Luttinger liquids”, after the effective low-energy theory in which spin and charge behave as separate degrees of freedom with independent energy scales. The “spin-incoherent Luttinger liquid” describes a finite-temperature regime that is realized when the temperature is very small relative to the Fermi energy, but larger than the characteristic spin energy scale. Similar physics can take place in the ground-state, when a Luttinger Liquid is coupled to a spin bath, which effectively introduces a “spin temperature”through its entanglement with the spin degree of freedom. We show that the spin-incoherent state can be exactly written as a factorized wave-function, with a spin wave-function that can be described within a valence bond formalism. This enables us to calculate exact expressions for the momentum distribution function and the entanglement entropy. This picture holds not only for two antiferromagnetically coupled t−J chains, but also for the t−J-Kondo chain with strongly interacting conduction electrons. We argue that this theory is quite universal and may describe a family of problems that could be dubbed “spin-incoherent”.
Rights© 2012 American Physical Society. The accepted manuscript version of this article appears in OpenBU by permission of the publisher.