Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland.
Phys Rev Lett. 2011 Jun 10;106(23):237003. doi: 10.1103/PhysRevLett.106.237003. Epub 2011 Jun 8.
We show, by means of low-energy muon-spin rotation measurements, that few-unit-cells thick La(2)CuO(4) layers synthesized digitally by molecular beam epitaxy are antiferromagnetically ordered. Below a thickness of about 5 CuO(2) layers the long-range ordered state breaks down, and a magnetic state appears with enhanced quantum fluctuations and a reduced spin stiffness. This magnetic state can exist in close proximity (few Å) to high-temperature superconducting layers, without transmitting supercurrents.
我们通过低能μ子自旋旋转测量表明，通过分子束外延数字合成的几单位晶胞厚 La(2)CuO(4)层是反铁磁有序的。在厚度约为 5 CuO(2)层以下，长程有序状态会瓦解，出现一个具有增强量子涨落和降低自旋刚度的磁状态。这个磁状态可以存在于高温超导层的近距离（几个Å）范围内，而不会传输超导电流。
