Two mode photon bunching effect as witness of quantum criticality in circuit QED  

作　　者：AI Qing1,WANG YingDan2,LONG GuiLu1,3 & SUN ChangPu4 1 Department of Physics,Tsinghua University,Beijing 100084,China 2 Department of Physics,University of Basel,Klingelbergstrasse 82,4056 Basel,Switzerland 3 Tsinghua National Laboratory for Information Science and Technology,Beijing 100084,China 4 Institute of Theoretical Physics,Chinese Academy of Sciences,Beijing 100080,China 

出　　处：《Science China(Physics,Mechanics & Astronomy)》2009年第12期1898-1905,共8页中国科学：物理学、力学、天文学（英文版）

基　　金：Supported by the National Basic Research Program of China (Grant No. 2006CB921106);the National Natural Science Foundation of China (Grant No. 10874098);the ECIST-FET Project EuroSQUIP, the Swiss SNF, and the NCCR Nanoscience

摘　　要：We suggest a scheme to probe critical phenomena at a quantum phase transition (QPT) using the quantum correlation of two photonic modes simultaneously coupled to a critical system. As an experimentally accessible physical implementation,a circuit QED system is formed by a capacitively coupled Josephson junction qubit array interacting with one superconducting transmission line resonator (TLR). It realizes an Ising chain in the transverse field (ICTF) which interacts with the two magnetic modes propagating in the TLR. We demonstrate that in the vicinity of criticality the originally independent fields tend to display photon bunching effects due to their interaction with the ICTF. Thus,the occurrence of the QPT is reflected by the quantum characteristics of the photonic fields.We suggest a scheme to probe critical phenomena at a quantum phase transition (QPT) using the quantum correlation of two photonic modes simultaneously coupled to a critical system. As an experimentally accessible physical implementation, a circuit QED system is formed by a capacitively coupled Josephson junction qubit array interacting with one superconducting transmission line resonator (TLR). It realizes an Ising chain in the transverse field (ICTF) which interacts with the two magnetic modes propagating in the TLR. We demonstrate that in the vicinity of criticality the originally independent fields tend to display photon bunching effects due to their interaction with the ICTF. Thus, the occurrence of the QPT is reflected by the quantum characteristics of the photonic fields.

关 键 词：quantum phase TRANSITION PHOTON BUNCHING CIRCUIT QED 

分 类 号：O413.2[理学—理论物理]