TY - JOUR

T1 - Breakdown of the Nagaoka phase in the two-dimensional (formula presented) model

AU - Eisenberg, E.

AU - Berkovits, R.

AU - Huse, David A.

AU - Altshuler, B. L.

PY - 2002

Y1 - 2002

N2 - In the limit of weak exchange J at low hole concentration (formula presented) the ground state of the two-dimensional (formula presented) model is believed to be ferromagnetic. We study the leading instability of this Nagaoka state, which emerges with increasing J. Both exact diagonalization of small clusters, and a semiclassical analytical calculation of larger systems show that above a certain critical value of the exchange, (formula presented) Nagaoka’s state is unstable to phase separation. In a finite-size system a bubble of antiferromagnetic Mott insulator appears in the ground state above this threshold. The size of this bubble depends on (formula presented) and scales as a power of the system size N.

AB - In the limit of weak exchange J at low hole concentration (formula presented) the ground state of the two-dimensional (formula presented) model is believed to be ferromagnetic. We study the leading instability of this Nagaoka state, which emerges with increasing J. Both exact diagonalization of small clusters, and a semiclassical analytical calculation of larger systems show that above a certain critical value of the exchange, (formula presented) Nagaoka’s state is unstable to phase separation. In a finite-size system a bubble of antiferromagnetic Mott insulator appears in the ground state above this threshold. The size of this bubble depends on (formula presented) and scales as a power of the system size N.

UR - http://www.scopus.com/inward/record.url?scp=85038344388&partnerID=8YFLogxK

U2 - 10.1103/PhysRevB.65.134437

DO - 10.1103/PhysRevB.65.134437

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AN - SCOPUS:85038344388

SN - 1098-0121

VL - 65

SP - 1

EP - 7

JO - Physical Review B - Condensed Matter and Materials Physics

JF - Physical Review B - Condensed Matter and Materials Physics

IS - 13

ER -