Sknepnek Rastko, Vojta Thomas, Vojta Matthias
Physics Department, University of Missouri, Rolla, Rolla, Missouri 65409, USA.
Phys Rev Lett. 2004 Aug 27;93(9):097201. doi: 10.1103/PhysRevLett.93.097201. Epub 2004 Aug 23.
We present Monte Carlo simulations of a two-dimensional bilayer quantum Heisenberg antiferromagnet with random dimer dilution. In contrast with exotic scaling scenarios found in other random quantum systems, the quantum phase transition in this system is characterized by a finite-disorder fixed point with power-law scaling. After accounting for corrections to scaling, with a leading irrelevant exponent of omega approximately 0.48, we find universal critical exponents z=1.310(6) and nu=1.16(3). We discuss the consequences of these findings and suggest new experiments.
我们展示了具有随机二聚体稀释的二维双层量子海森堡反铁磁体的蒙特卡罗模拟。与其他随机量子系统中发现的奇异标度情形不同，该系统中的量子相变由具有幂律标度的有限无序不动点表征。在考虑标度修正后，主导无关指数ω约为0.48，我们得到了普适临界指数z = 1.310(6)和ν = 1.16(3)。我们讨论了这些发现的后果并提出了新的实验。
