TY - JOUR

T1 - Critical properties of the spin-1/2 Heisenberg chain with frustration and bond alternation

AU - Okamoto, Kiyomi

AU - Nakamura, Tota

PY - 1997/9/21

Y1 - 1997/9/21

N2 - We study the S = 1/2 Heisenberg chain with frustration and alternation which is expressed by H = ∑j{[1 + (-1)jδ]Sj · Sj+1 + J2Sj · Sj+2}, both analytically and numerically. We focus on the J2 = 0.2411 case, where there is no marginal operator which brings about the logarithmic corrections in various quantities. By using the bosonization method, we calculate the energy gap, the change in the ground-state energy due to the alternation (so-called energy gain), the spin correlation and the string correlation (not only their exponents but also their amplitudes), and compare them with the results of the numerical diagonalization for finite systems. We point out the existence of the logarithmic correction in the energy gain despite the absence of the marginal operator. Taking into account this logarithmic correction, we can obtain a reasonable hyperscaling relation between the critical exponents of the energy gap and an energy gain from the numerical data.

AB - We study the S = 1/2 Heisenberg chain with frustration and alternation which is expressed by H = ∑j{[1 + (-1)jδ]Sj · Sj+1 + J2Sj · Sj+2}, both analytically and numerically. We focus on the J2 = 0.2411 case, where there is no marginal operator which brings about the logarithmic corrections in various quantities. By using the bosonization method, we calculate the energy gap, the change in the ground-state energy due to the alternation (so-called energy gain), the spin correlation and the string correlation (not only their exponents but also their amplitudes), and compare them with the results of the numerical diagonalization for finite systems. We point out the existence of the logarithmic correction in the energy gain despite the absence of the marginal operator. Taking into account this logarithmic correction, we can obtain a reasonable hyperscaling relation between the critical exponents of the energy gap and an energy gain from the numerical data.

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U2 - 10.1088/0305-4470/30/18/012

DO - 10.1088/0305-4470/30/18/012

M3 - Article

AN - SCOPUS:0031582731

VL - 30

SP - 6287

EP - 6298

JO - Journal of Physics A: Mathematical and Theoretical

JF - Journal of Physics A: Mathematical and Theoretical

SN - 1751-8113

IS - 18

ER -