Dalla Torre Emanuele G, Berg Erez, Altman Ehud
Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 76100, Israel.
Phys Rev Lett. 2006 Dec 31;97(26):260401. doi: 10.1103/PhysRevLett.97.260401. Epub 2006 Dec 27.
We investigate the phase diagram of spinless bosons with long range (variant 1/r(3)) repulsive interactions, relevant to ultracold polarized atoms or molecules, using density matrix renormalization group. Between the two conventional insulating phases, the Mott and density wave phases, we find a new phase possessing hidden order revealed by nonlocal string correlations analogous to those characterizing the Haldane gapped phase of integer spin chains. We develop a mean field theory that describes the low-energy excitations in all three insulating phases. This is used to calculate the absorption spectrum due to oscillatory lattice modulation. We predict a sharp resonance in the spectrum due to a collective excitation of the new phase that would provide clear evidence for the existence of this phase.
我们使用密度矩阵重整化群研究了与超冷极化原子或分子相关的、具有长程（1/r³形式）排斥相互作用的无自旋玻色子的相图。在两个传统绝缘相，即莫特相和密度波相之间，我们发现了一个具有隐藏序的新相，该隐藏序由非局域弦关联揭示，类似于表征整数自旋链的霍尔丹能隙相的那些关联。我们发展了一种平均场理论，该理论描述了所有三个绝缘相中的低能激发。这被用于计算由于振荡晶格调制引起的吸收光谱。我们预测光谱中会由于新相的集体激发而出现一个尖锐的共振，这将为该相的存在提供明确证据。
