We propose a potentially practical scheme for implementing an n-qubit Toffoli gate by elaborately controllingthe transport of ultracold ions through stationary laser beams.Conditioned on the uniform ionic transport ve...We propose a potentially practical scheme for implementing an n-qubit Toffoli gate by elaborately controllingthe transport of ultracold ions through stationary laser beams.Conditioned on the uniform ionic transport velocity,the n-qubit Toffoli gate can be realized with high fidelity and high successful probability under current experimentalconditions,which depends on a single resonant interaction with n trapped ions and has constant implementation timewith the increase of qubits.We show that the increase of the ion number can improve the fidelity and the successfulprobability of the Toffoli gate.展开更多
The femtosecond optical trapping capability and the effect of femtosecond laser pulses on cell viability were studied.The maximum lateral velocity at which the particles just failed to be trapped,together with the mea...The femtosecond optical trapping capability and the effect of femtosecond laser pulses on cell viability were studied.The maximum lateral velocity at which the particles just failed to be trapped,together with the measured average trapping power,were used to calculate the lateral trapping force(Q-value) .The viability of the cells after femtosecond laser trapping was ascertained by vital staining.Measurement of the Q-values shows that femtosecond optical tweezers are just as effective as continuous wave optical tweezers.The experiments demonstrate that there is a critical limit for exposure time at each corresponding laser power of femtosecond optical tweezers,and femtosecond laser tweezers are safe for optical trapping at low power with short exposure time.展开更多
We study the effects of electrolyte temperature on DNA molecule translocation experimentally without and with a temperature gradient across nanopore membranes.The same temperatures on both electrolyte chambers are fir...We study the effects of electrolyte temperature on DNA molecule translocation experimentally without and with a temperature gradient across nanopore membranes.The same temperatures on both electrolyte chambers are first considered.The DNA molecule translocation time is measured to be 2.44 ms at 2°C in both chambers,which is 1.57 times longer than at 20°C.Then the temperature difference effect is characterized in both chambers.The results show that the DNA translocation speed can be slowed down as long as one side temperature is lowered,irrespective of the temperature gradient direction.This indicates that the thermophoretic driving force generated by a temperature gradient has no obvious effect on the threading speed of DNA molecules,while the main reason for the slowed DNA translocation speed is the increased viscosity.Interestingly,the capture rate of DNA molecules is enhanced under a temperature gradient condition,and the capture rate during DNA translocation from hot side at 21°C to cold one at 2°C is 1.7 times larger than that under the condition of both chambers at 20°C.Finally,an optimized configuration is proposed to acquire higher capture rates and lower DNA translocation speeds.展开更多
基金supported by National Natural Science Foundation of China under Grant Nos.10774163 and 10774042partly by the National Fundamental Research Program of China under Grant Nos.2005CB724502 and 2006CB921203
文摘We propose a potentially practical scheme for implementing an n-qubit Toffoli gate by elaborately controllingthe transport of ultracold ions through stationary laser beams.Conditioned on the uniform ionic transport velocity,the n-qubit Toffoli gate can be realized with high fidelity and high successful probability under current experimentalconditions,which depends on a single resonant interaction with n trapped ions and has constant implementation timewith the increase of qubits.We show that the increase of the ion number can improve the fidelity and the successfulprobability of the Toffoli gate.
基金Supported by China Postdoctoral Science Foundation (No.20080440097)
文摘The femtosecond optical trapping capability and the effect of femtosecond laser pulses on cell viability were studied.The maximum lateral velocity at which the particles just failed to be trapped,together with the measured average trapping power,were used to calculate the lateral trapping force(Q-value) .The viability of the cells after femtosecond laser trapping was ascertained by vital staining.Measurement of the Q-values shows that femtosecond optical tweezers are just as effective as continuous wave optical tweezers.The experiments demonstrate that there is a critical limit for exposure time at each corresponding laser power of femtosecond optical tweezers,and femtosecond laser tweezers are safe for optical trapping at low power with short exposure time.
基金supported by the National Basic Research Program of China("973"Project)(Grant Nos.2011CB707601 and 2011CB707605)the National Natural Science Foundation of China(Grants Nos.50925519 and 51375092)+1 种基金supported by the Scientific Research Foundation of Graduate School of Southeast University(Grant No.YBJJ1004)supported by the Fundamental Research Funds for the Central Universities and the Innovative Project for Graduate Students of Jiangsu Province(Grant No.KYLX_0100)
文摘We study the effects of electrolyte temperature on DNA molecule translocation experimentally without and with a temperature gradient across nanopore membranes.The same temperatures on both electrolyte chambers are first considered.The DNA molecule translocation time is measured to be 2.44 ms at 2°C in both chambers,which is 1.57 times longer than at 20°C.Then the temperature difference effect is characterized in both chambers.The results show that the DNA translocation speed can be slowed down as long as one side temperature is lowered,irrespective of the temperature gradient direction.This indicates that the thermophoretic driving force generated by a temperature gradient has no obvious effect on the threading speed of DNA molecules,while the main reason for the slowed DNA translocation speed is the increased viscosity.Interestingly,the capture rate of DNA molecules is enhanced under a temperature gradient condition,and the capture rate during DNA translocation from hot side at 21°C to cold one at 2°C is 1.7 times larger than that under the condition of both chambers at 20°C.Finally,an optimized configuration is proposed to acquire higher capture rates and lower DNA translocation speeds.
