Following a recent proposal by Dhar et al （2006 Phys. Rev. Lett. 96 100405）, we demonstrate experimentally the preservation of quantum states in a two-qubit system based on a super-Zeno effect using liquid-state nuc...Following a recent proposal by Dhar et al （2006 Phys. Rev. Lett. 96 100405）, we demonstrate experimentally the preservation of quantum states in a two-qubit system based on a super-Zeno effect using liquid-state nuclear magnetic resonance techniques. Using inverting radiofrequency pulses and delicately selecting time intervals between two pulses, we suppress the effect of decoherence of quantum states. We observe that preservation of the quantum state ｜11〉 with the super-Zeno effect is three times more efficient than the ordinary one with the standard Zeno effect.展开更多
We experimentally demonstrate the quantum anti-Zeno effect in a two-level system based on a single trapped ion ^（40）Ca~＋. In the large detuning regime, we show that the transfer from the ground state to the excited...We experimentally demonstrate the quantum anti-Zeno effect in a two-level system based on a single trapped ion ^（40）Ca~＋. In the large detuning regime, we show that the transfer from the ground state to the excited state can be remarkably enhanced by the inserted projection measurements. The inserted measurements in our experiment are realized by the electron shelving technique. Compared to the ideal projection measurement, which makes the quantum state collapse instantaneously, a practical electron shelving process needs a finite time duration. The minimum time for this collapse process is shown to be inversely proportional to the square of the coupling strength between the measurement laser and the system.展开更多
Our main aim is to prove a more general version of the quantum Zeno effect. Then we discuss some examples of the quantum Zeno effect. Furthermore, we discuss a possibility that based on the quantum Zeno effect and cer...Our main aim is to prove a more general version of the quantum Zeno effect. Then we discuss some examples of the quantum Zeno effect. Furthermore, we discuss a possibility that based on the quantum Zeno effect and certain experiments one could check whether, from the statistical point of view, a concrete system behaves like a quantum system. The more general version of quantum Zeno effect can be helpful to prove that the brain acts like in a quantum system. The proof of our main result is based on certain formulas describing probability distributions of time series related to quantum measurements.展开更多
In this paper, we study a quantum anti-Zeno effect (QAZE) purely induced by repetitive measurements foran artificial atom interacting with a structured bath.This bath can be artificially realized with coupled resonato...In this paper, we study a quantum anti-Zeno effect (QAZE) purely induced by repetitive measurements foran artificial atom interacting with a structured bath.This bath can be artificially realized with coupled resonators in onedimension and possesses photonic band structure like Bloch electron in a periodic potential.In the presence of repetitivemeasurements, the pure QAZE is discovered as the observable decay is not negligible even for the atomic energy levelspacing outside of the energy band of the artificial bath.If there were no measurements, the decay would not happenoutside of the band.In this sense, the enhanced decay is completely induced by measurements through the relaxationchannels provided by the bath.Besides, we also discuss the controversial golden rule decay rates originated from the vanHove's singularities and the effects of the counter-rotating terms.展开更多
Quantum Zeno effect with mixed initial state is studied here. Frequent projective measurements performed on a bipartite joint pure state system will result in the quantum Zeno effect on the subsystem of interest. This...Quantum Zeno effect with mixed initial state is studied here. Frequent projective measurements performed on a bipartite joint pure state system will result in the quantum Zeno effect on the subsystem of interest. This shows the existence of Quantum Zeno effect in the system with mixed initial states.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos 10374103, 10574143 and 10874206)the National Key Basic Research Program of China (Grant No 2006CB921203)
文摘Following a recent proposal by Dhar et al （2006 Phys. Rev. Lett. 96 100405）, we demonstrate experimentally the preservation of quantum states in a two-qubit system based on a super-Zeno effect using liquid-state nuclear magnetic resonance techniques. Using inverting radiofrequency pulses and delicately selecting time intervals between two pulses, we suppress the effect of decoherence of quantum states. We observe that preservation of the quantum state ｜11〉 with the super-Zeno effect is three times more efficient than the ordinary one with the standard Zeno effect.
基金Project supported by the National Basic Research Program of China(Grant No.2016YFA0301903)the National Natural Science Foundation of China(Grant Nos.11174370,11304387,61632021,11305262,11574398,and N 61205108)the Research Plan Project of National University of Defense Technology,China(Grant No.ZK16-03-04)
文摘We experimentally demonstrate the quantum anti-Zeno effect in a two-level system based on a single trapped ion ^（40）Ca~＋. In the large detuning regime, we show that the transfer from the ground state to the excited state can be remarkably enhanced by the inserted projection measurements. The inserted measurements in our experiment are realized by the electron shelving technique. Compared to the ideal projection measurement, which makes the quantum state collapse instantaneously, a practical electron shelving process needs a finite time duration. The minimum time for this collapse process is shown to be inversely proportional to the square of the coupling strength between the measurement laser and the system.
文摘Our main aim is to prove a more general version of the quantum Zeno effect. Then we discuss some examples of the quantum Zeno effect. Furthermore, we discuss a possibility that based on the quantum Zeno effect and certain experiments one could check whether, from the statistical point of view, a concrete system behaves like a quantum system. The more general version of quantum Zeno effect can be helpful to prove that the brain acts like in a quantum system. The proof of our main result is based on certain formulas describing probability distributions of time series related to quantum measurements.
基金Supported by the Natural Science Foundation of China under Grant Nos.10974209 and 10935010 the National 973 Program under Grant No.2006CB921205China Postdoctoral Science Foundation under Grant No.20100470584
文摘In this paper, we study a quantum anti-Zeno effect (QAZE) purely induced by repetitive measurements foran artificial atom interacting with a structured bath.This bath can be artificially realized with coupled resonators in onedimension and possesses photonic band structure like Bloch electron in a periodic potential.In the presence of repetitivemeasurements, the pure QAZE is discovered as the observable decay is not negligible even for the atomic energy levelspacing outside of the energy band of the artificial bath.If there were no measurements, the decay would not happenoutside of the band.In this sense, the enhanced decay is completely induced by measurements through the relaxationchannels provided by the bath.Besides, we also discuss the controversial golden rule decay rates originated from the vanHove's singularities and the effects of the counter-rotating terms.
基金Supported by National Natural Science Foundation of China under Grant Nos. 10704001, 61073048, and 11005029the Key Project of Chinese Ministry of Education under Grant No. 210092+2 种基金the Key Program of the Education Department of Anhui Province under Grant Nos. KJ2008A28ZC, 2010SQRL153ZD, and KJ2010A287the "211" Project of Anhui University, the Personnel Department of Anhui ProvinceAnhui Key Laboratory of Information Materials and Devices Anhui University
文摘Quantum Zeno effect with mixed initial state is studied here. Frequent projective measurements performed on a bipartite joint pure state system will result in the quantum Zeno effect on the subsystem of interest. This shows the existence of Quantum Zeno effect in the system with mixed initial states.
基金supported by the NSFC under Grant(11074079)the Ph.D.Programs Foundation of Ministry of Education of China under Grant(20104407110009)Natural Science Foundation of Shanghai(15ZR1430600)
