We propose a non-stationary method to measure the energy relaxation time of Josephson tunnel junctions from microwave enhanced escape phenomena. Compared with the previous methods, our method possesses simple and accu...We propose a non-stationary method to measure the energy relaxation time of Josephson tunnel junctions from microwave enhanced escape phenomena. Compared with the previous methods, our method possesses simple and accurate features. Moreover, having determined the energy relaxation time, we can further obtain the coupling strength between the microwave source and the junction by changing the microwave power.展开更多
Nb/Al-AlOx/Nb tunnel junctions with controllable critical current density Jc are fabricated using the standard selective Nb etching process. Tunnel barriers are formed in different oxygen exposure conditions （oxygen ...Nb/Al-AlOx/Nb tunnel junctions with controllable critical current density Jc are fabricated using the standard selective Nb etching process. Tunnel barriers are formed in different oxygen exposure conditions （oxygen pressure P and oxidation time t）, giving rise to Jc ranging from 100A/cm^2 to above 2000A/cm^2. Jc shows a familiar linear dependence on P×t in logarithmic scales. We calculate the energy levels of the phase- and flux-type qubits using the achievable junction parameters and show that the fabricated Nb/Al-AlOx/Nb tunnel junctions can be used conveniently for quantum computation applications in the future.展开更多
Many researchers conceive communication in Microtubules (MTs), and established theoretical models to show both classical and quantum information processing. In this paper, we studied the usually neglected interactions...Many researchers conceive communication in Microtubules (MTs), and established theoretical models to show both classical and quantum information processing. In this paper, we studied the usually neglected interactions between the electronic dipole of water molecules in microtubules and the quantized electromagnetic radiation field. We find that the emergence collective coherent radiation, and it can turn into macroscopic quantum superposition state when passing through MTs. This could have a fundamental role in the quantum information processing.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 10674062, the Natural Science Foundation of Jiangsu Province （BK2006118）, and the Doctoral Funds of Ministry of Education of China （20060284022）. We thank Sun Guozhu, Qing Lan and Mao Ting for useful discussions.
文摘We propose a non-stationary method to measure the energy relaxation time of Josephson tunnel junctions from microwave enhanced escape phenomena. Compared with the previous methods, our method possesses simple and accurate features. Moreover, having determined the energy relaxation time, we can further obtain the coupling strength between the microwave source and the junction by changing the microwave power.
基金Project supported by the National Natural Science Foundation of China (Grant Nos 10534060 and 10874231)the Ministry of Science and Technology of China (Grant Nos 2006CB601007, 2006CB921107, and 2009CB929102)
文摘Nb/Al-AlOx/Nb tunnel junctions with controllable critical current density Jc are fabricated using the standard selective Nb etching process. Tunnel barriers are formed in different oxygen exposure conditions （oxygen pressure P and oxidation time t）, giving rise to Jc ranging from 100A/cm^2 to above 2000A/cm^2. Jc shows a familiar linear dependence on P×t in logarithmic scales. We calculate the energy levels of the phase- and flux-type qubits using the achievable junction parameters and show that the fabricated Nb/Al-AlOx/Nb tunnel junctions can be used conveniently for quantum computation applications in the future.
文摘Many researchers conceive communication in Microtubules (MTs), and established theoretical models to show both classical and quantum information processing. In this paper, we studied the usually neglected interactions between the electronic dipole of water molecules in microtubules and the quantized electromagnetic radiation field. We find that the emergence collective coherent radiation, and it can turn into macroscopic quantum superposition state when passing through MTs. This could have a fundamental role in the quantum information processing.
