Uniaxial tension tests were conducted on single-edge-notched tensile specimens of pure molybdenum with a mesh grid pattern in front of the notch. A series of images of crack initialization and propagation with a disto...Uniaxial tension tests were conducted on single-edge-notched tensile specimens of pure molybdenum with a mesh grid pattern in front of the notch. A series of images of crack initialization and propagation with a distorted mesh grid pattern were obtained by means of in situ scanning electron microscopy. Strain fields around the crack tip were mapped successively using geometric phase analysis and digital image correlation techniques, and then compared with the predictions obtained through linear elastic fracture mechanics （LEFM）. The comparison shows that the measured strain distribution ahead of the crack tip is consistent with the LEFM predictions of up to 25 μm from the crack tip.展开更多
Geometric phases have natural manifestations in large deformations of geometrically exact rods. The primary concerns of this article are the physical implications and observable consequences of geometric phases arisin...Geometric phases have natural manifestations in large deformations of geometrically exact rods. The primary concerns of this article are the physical implications and observable consequences of geometric phases arising from the deformed patterns exhibited by a rod subjected to end moments. This mechanical problem is classical and has a long tradition dating back to Kirchhoff. However, the perspective from geometric phases seems to go more deeply into relations between local strain states and global geometry of shapes, and infuses genuinely new insights and better understanding, which enable one to describe this kind of deformation in a neat and elegant way. On the other hand, visual representations of these deformations provide beautiful illustrations of geometric phases and render the meaning of the abstract concept of holonomy more direct and transparent.展开更多
We propose a scheme for the realization of unconventional geometric two-qubit phase gates with two identical two-level ions, In the present scheme, the two ions are simultaneously illuminated by a standing-wave laser ...We propose a scheme for the realization of unconventional geometric two-qubit phase gates with two identical two-level ions, In the present scheme, the two ions are simultaneously illuminated by a standing-wave laser pulse with its pulse frequency being tuned to the ionic transition. The gate operation time can be much shorter, making the system robust against decoherence. In addition, we choose the appropriate experimental parameters to construct the geometric phase gate in one step, and thus avoid implementing the pure geometric single qubit operation.展开更多
The geometric phase has become a fundamental concept in many fields of physics since it was revealed. Recently, the study of the geometric phase has attracted considerable attention in the context of quantum phase tra...The geometric phase has become a fundamental concept in many fields of physics since it was revealed. Recently, the study of the geometric phase has attracted considerable attention in the context of quantum phase transition, where the ground state properties of the system experience a dramatic change induced by a variation of an external parameter. In this work, we experimentally measure the ground-state geometric phase of the three-spin XY model by utilizing the nuclear magnetic resonance technique. The experimental results indicate that the geometric phase could be used as a fingerprint of the ground-state quantum phase transition of many-body systems.展开更多
We propose a scheme for the implementation of remote controlled-NOT gates and entanglement swapping via geometric phase gates in ion-trap systems. The proposed scheme uses the two ground states of the A-type ions as m...We propose a scheme for the implementation of remote controlled-NOT gates and entanglement swapping via geometric phase gates in ion-trap systems. The proposed scheme uses the two ground states of the A-type ions as memory instead of the vibrational mode. And the system is robust against the spontaneous radiation and the dephasing.展开更多
We consider a qubit symmetrically and transversely coupled to an XY spin chain with Dzyaloshinsky-Moriya（DM） interaction in the presence of a transverse magnetic field.An analytical expression for the geometric phas...We consider a qubit symmetrically and transversely coupled to an XY spin chain with Dzyaloshinsky-Moriya（DM） interaction in the presence of a transverse magnetic field.An analytical expression for the geometric phase of the qubit is obtained in the weak coupling limit.We find that the modification of the geometrical phase induced by the spin chain environment is greatly enhanced by DM interaction in the weak coupling limit around the quantum phase transition point of the spin chain.展开更多
We present an alternative scheme for implementing the unconventional geometric two-qubit phase gate and prepar- ing multiqubit entanglement by using a frequency-modulated laser field to simultaneously illuminate all i...We present an alternative scheme for implementing the unconventional geometric two-qubit phase gate and prepar- ing multiqubit entanglement by using a frequency-modulated laser field to simultaneously illuminate all ions. Selecting the index of modulation yields selective mechanisms for coupling and decoupling between the internal and the external states of the ions. By the selective mechanisms, we obtain the unconventional geometric two-qubit phase gate, multiparticle Greenberger-Horne-Zeilinger states and highly entangled cluster states. Our scheme is insensitive to the thermal motion of the ions.展开更多
The generalization of geometric phase from the pure states to the mixed states may have potential applications in constructing geometric quantum gates. We here investigate the mixed state geometric phases and visibili...The generalization of geometric phase from the pure states to the mixed states may have potential applications in constructing geometric quantum gates. We here investigate the mixed state geometric phases and visibilities of the trapped ion system in both non-degenerate and degenerate cases. In the proposed quantum system, the geometric phases are determined by the evolution time, the initial states of trapped ions, and the initial states of photons. Moreover, special periods are gained under which the geometric phases do not change with the initial states changing of photon parts in both non-degenerate and degenerate cases. The high detection efficiency in the ion trap system implies that the mixed state geometric phases proposed here can be easily tested.展开更多
We obtained the ground-state energy level and associated geometric phase in the Dicke model with the dipoledipole interactions analytically by the Holstein-Primakoff transformation and the boson expansion approach in ...We obtained the ground-state energy level and associated geometric phase in the Dicke model with the dipoledipole interactions analytically by the Holstein-Primakoff transformation and the boson expansion approach in the thermodynamic limit. The nonadiabatic geometric phase induced by the photon field was derived with the time-dependent unitary transformation. It is shown that dipole-dipole interactions have a deep influence on scaled behavior of the geometric phase at the critical point.展开更多
The geometric phase of the bipartite Heisenberg spin-1/2 system with one spin driven by rotating magnetic field is investigated. It is found that in the one-site drive case, the intersubsystem coupling can be equivale...The geometric phase of the bipartite Heisenberg spin-1/2 system with one spin driven by rotating magnetic field is investigated. It is found that in the one-site drive case, the intersubsystem coupling can be equivalent to a static quasi-magnetic field in the parameter space. This perspective has satisfactorily explained the irregular asymptote effect of geometric phase. We discuss the property of the two-site magnetic drive spin system and discover that a stationary state with no geometric phase shift is generated.展开更多
We consider a two-qubit system described by the Heisenberg XY model with Dzyaloshinski Moriya （DM） anisotropic interaction in a perpendicular magnetic field to investigate the relation between entanglement, geometri...We consider a two-qubit system described by the Heisenberg XY model with Dzyaloshinski Moriya （DM） anisotropic interaction in a perpendicular magnetic field to investigate the relation between entanglement, geometric phase and quantum phase transition （QPT）. It is shown that the DM interaction has an effect on the critical boundary. The combination of entanglement and geometric phase may characterize QPT completely. Their jumps mean that the occurrence of QPT and inversely the QPT at the critical point at least corresponds to a jump of one of them.展开更多
We propose a scheme for realizing a controlled geometric phase gate for two neutral atoms.We apply thestimulated Raman adiabatic passage to transfer atoms from their ground states into Rydberg excited states, and use ...We propose a scheme for realizing a controlled geometric phase gate for two neutral atoms.We apply thestimulated Raman adiabatic passage to transfer atoms from their ground states into Rydberg excited states, and use theRydberg interaction induced energy shifts to generate geometric phase and construct quantum gates.展开更多
Motivated by recent developments in quantum fidelity and fidelity susceptibility, we study relations among Lie algebra, fidelity susceptibility and quantum phase transition for a two-state system and the Lipkin-Meshko...Motivated by recent developments in quantum fidelity and fidelity susceptibility, we study relations among Lie algebra, fidelity susceptibility and quantum phase transition for a two-state system and the Lipkin-Meshkov Glick model. We obtain the fidelity susceptibilities for SU（2） and SU（1, 1） algebraic structure models. From this relation, the validity of the fidelity susceptibility to signal for the quantum phase transition is also verified in these two systems. At the same time, we obtain the geometric phases in these two systems by calculating the fidelity susceptibility. In addition, the new method of calculating fidelity susceptibility is used to explore the two-dimensional XXZ model and the Bose-Einstein condensate （BEC）.展开更多
We study geometric phases of the ground states of inhomogeneous XY spin chains in transverse fields with Dzyaloshinski--Moriya （DM） interaction, and investigate the effect of the DM interaction on the quantum phase ...We study geometric phases of the ground states of inhomogeneous XY spin chains in transverse fields with Dzyaloshinski--Moriya （DM） interaction, and investigate the effect of the DM interaction on the quantum phase transition （QPT） of such spin chains. The results show that the DM interaction could influence the distribution of the regions of QPTs but could not produce new critical points for the spin-chain. This study extends the relation between geometric phases and QPTs.展开更多
We investigate a novel spatial geometric phase of hybrid-polarized vector fields consisting of linear, elliptical and circular polarizations by Young＇s two-slit interferometer instead of the widely used Mach-Zehnder ...We investigate a novel spatial geometric phase of hybrid-polarized vector fields consisting of linear, elliptical and circular polarizations by Young＇s two-slit interferometer instead of the widely used Mach-Zehnder interferometer. This spatial geometric phase can be manipulated by engineering the spatial configuration of hybrid polarizations, and is directly related to the topological charge, the local states of polarization and the rotational symmetry of hybrid-polarized vector optical fields. The unique feature of geometric phase has implications in quantum information science as well as other physical systems such as electron vortex beams.展开更多
Utilizing the geometric phase(GP)acquired in a quantum evolution,we manifest the thermality and quantum nature of the Unruh effect of an accelerating detector.We consider an UDW detector coupling to a conformal field ...Utilizing the geometric phase(GP)acquired in a quantum evolution,we manifest the thermality and quantum nature of the Unruh effect of an accelerating detector.We consider an UDW detector coupling to a conformal field in Minkowski spacetime,whose response spectrum exhibits an intermediate statistics of(1+1)anyon field.We find that comparing to an inertial moving detector,the GP in accelerating frame is modified after the nonunitary evolution of the detector due to the Unruh effect.We show that such modification can distinguish the different thermalizing ways of the detector,which depends on the scaling dimension of the conformal primary field.Finally,we estimate the difference between the GP under the Unruh radiation and that in a thermal bath for a static observer,which reveals the quantum origin of the Unruh effect rather than a conventional thermal noise.展开更多
We present an experiment of observing the geometric phase in a superconducting circuit where the resonator and the qutrit energy levels are dispersively coupled. The drive applied to the resonator displaces its state ...We present an experiment of observing the geometric phase in a superconducting circuit where the resonator and the qutrit energy levels are dispersively coupled. The drive applied to the resonator displaces its state components associated with the qutrit＇s ground state and first-excited state along different circular trajectories in phase space. We identify the resonator＇s phase-space trajectories by Wigner tomography using an ancilla qubit, following which we observe the difference between the geometric phases associated with these trajectories using Ramsey interferometry. This geometric phase is further used to construct the single-qubit It-phase gate with a process fidelity of 0.851± 0.001.展开更多
In this work we investigated the geometric phases of a qubit-oscillator system beyond the conventional rotating- wave approximation. We find that in the limiting of weak coupling the results coincide with that obtaine...In this work we investigated the geometric phases of a qubit-oscillator system beyond the conventional rotating- wave approximation. We find that in the limiting of weak coupling the results coincide with that obtained under rotating-wave approximation while there exists an increasing difference with the increase of coupling constant. It was shown that the geometric phase is symmetric with respect to the sign of the detuning of the quantized field from the one-photon resonance under the conventional rotating-wave approximation while a red-blue detuning asymmetry occurs beyond the conventional rotating-wave approximation.展开更多
We study theoretically the nonadiabatic geometric phase of a doubly driven two-level system with an additional relative phase between the two driving modes introduced in. It is shown that the time evolution of the sys...We study theoretically the nonadiabatic geometric phase of a doubly driven two-level system with an additional relative phase between the two driving modes introduced in. It is shown that the time evolution of the system strongly depends on this relative phase. The condition for the system returning to its initial state after a single period is given by the means of the Landau–Zener–Stückelberg–Majorana destructive interference. The nonadiabatic geometric phase accompanying a cyclic evolution is shown to be related to the Stokes phase as well as this relative phase. By controlling the relative phase, the geometric phase can characterize two distinct phases in the adiabatic limit.展开更多
We analyze the effect of stochastic dephasing on geometric phases. The result implies that the correction of geometric phases relies on not only the fluctuation of the random variable in the stochastic process, but al...We analyze the effect of stochastic dephasing on geometric phases. The result implies that the correction of geometric phases relies on not only the fluctuation of the random variable in the stochastic process, but also the frequency of the system.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 11562016 and 11672175)
文摘Uniaxial tension tests were conducted on single-edge-notched tensile specimens of pure molybdenum with a mesh grid pattern in front of the notch. A series of images of crack initialization and propagation with a distorted mesh grid pattern were obtained by means of in situ scanning electron microscopy. Strain fields around the crack tip were mapped successively using geometric phase analysis and digital image correlation techniques, and then compared with the predictions obtained through linear elastic fracture mechanics （LEFM）. The comparison shows that the measured strain distribution ahead of the crack tip is consistent with the LEFM predictions of up to 25 μm from the crack tip.
文摘Geometric phases have natural manifestations in large deformations of geometrically exact rods. The primary concerns of this article are the physical implications and observable consequences of geometric phases arising from the deformed patterns exhibited by a rod subjected to end moments. This mechanical problem is classical and has a long tradition dating back to Kirchhoff. However, the perspective from geometric phases seems to go more deeply into relations between local strain states and global geometry of shapes, and infuses genuinely new insights and better understanding, which enable one to describe this kind of deformation in a neat and elegant way. On the other hand, visual representations of these deformations provide beautiful illustrations of geometric phases and render the meaning of the abstract concept of holonomy more direct and transparent.
基金Project supported by the National Natural Science Foundation of China （Grant No 10574022）, and the Funds of the Natural Science of Fujian Province, China （Grant Nos Z0512006 and A0210014）.
文摘We propose a scheme for the realization of unconventional geometric two-qubit phase gates with two identical two-level ions, In the present scheme, the two ions are simultaneously illuminated by a standing-wave laser pulse with its pulse frequency being tuned to the ionic transition. The gate operation time can be much shorter, making the system robust against decoherence. In addition, we choose the appropriate experimental parameters to construct the geometric phase gate in one step, and thus avoid implementing the pure geometric single qubit operation.
基金Supported by the National Key Basic Research Program under Grant Nos 2013CB921800 and 2014CB848700the National Science Fund for Distinguished Young Scholars under Grant No 11425523+4 种基金the National Natural Science Foundation of China under Grant Nos 11375167,11227901,91021005 and 11575173the Strategic Priority Research Program(B)of the Chinese Academy of Sciences under Grant No XDB01030400the Research Fund for the Doctoral Program of Higher Education of China under Grant No 20113402110044the China Postdoctoral Science Foundationthe Fundamental Research Funds for the Central Universities
文摘The geometric phase has become a fundamental concept in many fields of physics since it was revealed. Recently, the study of the geometric phase has attracted considerable attention in the context of quantum phase transition, where the ground state properties of the system experience a dramatic change induced by a variation of an external parameter. In this work, we experimentally measure the ground-state geometric phase of the three-spin XY model by utilizing the nuclear magnetic resonance technique. The experimental results indicate that the geometric phase could be used as a fingerprint of the ground-state quantum phase transition of many-body systems.
基金Project supported by the National Natural Science Foundation (Grant Nos 10574022 and 10575022)the Funds of the Natural Science of Fujian Province, China (Grant No Z0512006)
文摘We propose a scheme for the implementation of remote controlled-NOT gates and entanglement swapping via geometric phase gates in ion-trap systems. The proposed scheme uses the two ground states of the A-type ions as memory instead of the vibrational mode. And the system is robust against the spontaneous radiation and the dephasing.
基金Project supported by the National Basic Research Program of China (Grant No. 2010CB923102)the Special Prophase Project on the National Basic Research Program of China (Grant No. 2011CB311807)the National Natural Science Foundation of China (Grant No. 11074199)
文摘We consider a qubit symmetrically and transversely coupled to an XY spin chain with Dzyaloshinsky-Moriya（DM） interaction in the presence of a transverse magnetic field.An analytical expression for the geometric phase of the qubit is obtained in the weak coupling limit.We find that the modification of the geometrical phase induced by the spin chain environment is greatly enhanced by DM interaction in the weak coupling limit around the quantum phase transition point of the spin chain.
基金Project supported by the National Basic Research Program of China (Grant No. 2005CB724508)the Scientific Research Foundation of Jiangxi Provincial Department of Education,China (Grant No. GJJ10133)the Foundation of Talent of Jinggangof Jiangxi Province,China (Grant No. 2008DQ00400)
文摘We present an alternative scheme for implementing the unconventional geometric two-qubit phase gate and prepar- ing multiqubit entanglement by using a frequency-modulated laser field to simultaneously illuminate all ions. Selecting the index of modulation yields selective mechanisms for coupling and decoupling between the internal and the external states of the ions. By the selective mechanisms, we obtain the unconventional geometric two-qubit phase gate, multiparticle Greenberger-Horne-Zeilinger states and highly entangled cluster states. Our scheme is insensitive to the thermal motion of the ions.
基金The project supported by the Natural Science Foundation of Education Bureau of Jiangsu Province of China under Grant No. 05KJB140008. The author is grateful to Prof. Z.D. Wang, Dr. S.L. Zhu, and Prof. Z.C. Dong for critical reading of the manuscript and useful suggestions.
文摘The generalization of geometric phase from the pure states to the mixed states may have potential applications in constructing geometric quantum gates. We here investigate the mixed state geometric phases and visibilities of the trapped ion system in both non-degenerate and degenerate cases. In the proposed quantum system, the geometric phases are determined by the evolution time, the initial states of trapped ions, and the initial states of photons. Moreover, special periods are gained under which the geometric phases do not change with the initial states changing of photon parts in both non-degenerate and degenerate cases. The high detection efficiency in the ion trap system implies that the mixed state geometric phases proposed here can be easily tested.
文摘We obtained the ground-state energy level and associated geometric phase in the Dicke model with the dipoledipole interactions analytically by the Holstein-Primakoff transformation and the boson expansion approach in the thermodynamic limit. The nonadiabatic geometric phase induced by the photon field was derived with the time-dependent unitary transformation. It is shown that dipole-dipole interactions have a deep influence on scaled behavior of the geometric phase at the critical point.
基金The project supported by National Natural Science Foundation of China under Grant No. 20376054
文摘The geometric phase of the bipartite Heisenberg spin-1/2 system with one spin driven by rotating magnetic field is investigated. It is found that in the one-site drive case, the intersubsystem coupling can be equivalent to a static quasi-magnetic field in the parameter space. This perspective has satisfactorily explained the irregular asymptote effect of geometric phase. We discuss the property of the two-site magnetic drive spin system and discover that a stationary state with no geometric phase shift is generated.
基金Project supported by the Natural Science Foundation for Young Scientists of Shanxi Province of China (Grant No. 2007021001)the Science and Technology Key Item of Chinese Ministry of Education (Grant No. 207017)+1 种基金National Fundamental Fund of Personnel Training (Grant No. J0730317)the National Natural Science Foundation of China (Grant No. 10774094)
文摘We consider a two-qubit system described by the Heisenberg XY model with Dzyaloshinski Moriya （DM） anisotropic interaction in a perpendicular magnetic field to investigate the relation between entanglement, geometric phase and quantum phase transition （QPT）. It is shown that the DM interaction has an effect on the critical boundary. The combination of entanglement and geometric phase may characterize QPT completely. Their jumps mean that the occurrence of QPT and inversely the QPT at the critical point at least corresponds to a jump of one of them.
基金Supported by the National Natural Science Foundation of China under Grant No.10974028 the Doctoral Foundation of the Ministry of Education of China under Grant No.20093514110009+1 种基金 the Natural Science Foundation of Fujian Province under Grant No.2009J06002Funds from the State Key Laboratory Breeding Base of Photocatalysis,Fuzhou University
文摘We propose a scheme for realizing a controlled geometric phase gate for two neutral atoms.We apply thestimulated Raman adiabatic passage to transfer atoms from their ground states into Rydberg excited states, and use theRydberg interaction induced energy shifts to generate geometric phase and construct quantum gates.
基金supported by the National Natural Science Foundation of China (Grant No. 11075101)the Shanghai Leading Academic Discipline Project,China (Grant No. S30105)the Shanghai Research Foundation,China (Grant No. 07d222020)
文摘Motivated by recent developments in quantum fidelity and fidelity susceptibility, we study relations among Lie algebra, fidelity susceptibility and quantum phase transition for a two-state system and the Lipkin-Meshkov Glick model. We obtain the fidelity susceptibilities for SU（2） and SU（1, 1） algebraic structure models. From this relation, the validity of the fidelity susceptibility to signal for the quantum phase transition is also verified in these two systems. At the same time, we obtain the geometric phases in these two systems by calculating the fidelity susceptibility. In addition, the new method of calculating fidelity susceptibility is used to explore the two-dimensional XXZ model and the Bose-Einstein condensate （BEC）.
基金Project supported by National Natural Science Foundation of China (Grant Nos. 10847108 and 10775023)
文摘We study geometric phases of the ground states of inhomogeneous XY spin chains in transverse fields with Dzyaloshinski--Moriya （DM） interaction, and investigate the effect of the DM interaction on the quantum phase transition （QPT） of such spin chains. The results show that the DM interaction could influence the distribution of the regions of QPTs but could not produce new critical points for the spin-chain. This study extends the relation between geometric phases and QPTs.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11534006,11674184 and 11374166the Natural Science Foundation of Tianjin under Grant No 16JC2DJC31300Collaborative Innovation Center of Extreme Optics
文摘We investigate a novel spatial geometric phase of hybrid-polarized vector fields consisting of linear, elliptical and circular polarizations by Young＇s two-slit interferometer instead of the widely used Mach-Zehnder interferometer. This spatial geometric phase can be manipulated by engineering the spatial configuration of hybrid polarizations, and is directly related to the topological charge, the local states of polarization and the rotational symmetry of hybrid-polarized vector optical fields. The unique feature of geometric phase has implications in quantum information science as well as other physical systems such as electron vortex beams.
基金Project supported by the National Natural Science Foundation of China(Grant No.12075178)Natural Science Basic Research Plan in Shaanxi Province of China(Grant No.2018JM1049)。
文摘Utilizing the geometric phase(GP)acquired in a quantum evolution,we manifest the thermality and quantum nature of the Unruh effect of an accelerating detector.We consider an UDW detector coupling to a conformal field in Minkowski spacetime,whose response spectrum exhibits an intermediate statistics of(1+1)anyon field.We find that comparing to an inertial moving detector,the GP in accelerating frame is modified after the nonunitary evolution of the detector due to the Unruh effect.We show that such modification can distinguish the different thermalizing ways of the detector,which depends on the scaling dimension of the conformal primary field.Finally,we estimate the difference between the GP under the Unruh radiation and that in a thermal bath for a static observer,which reveals the quantum origin of the Unruh effect rather than a conventional thermal noise.
基金Project supported by the National Basic Research Program of China(Grant No.2014CB921201)the National Natural Science Foundation of China(Grant Nos.11434008 and 11574380)
文摘We present an experiment of observing the geometric phase in a superconducting circuit where the resonator and the qutrit energy levels are dispersively coupled. The drive applied to the resonator displaces its state components associated with the qutrit＇s ground state and first-excited state along different circular trajectories in phase space. We identify the resonator＇s phase-space trajectories by Wigner tomography using an ancilla qubit, following which we observe the difference between the geometric phases associated with these trajectories using Ramsey interferometry. This geometric phase is further used to construct the single-qubit It-phase gate with a process fidelity of 0.851± 0.001.
基金supported by the National Natural Science Foundation of China (Grant Nos. 11075099, 11047167, and 11105087)the Programme of State Key Laboratory of Quantum Optics and Quantum Optics Devices (Grant No. KF201002)+1 种基金the National Fundamental Fund of Personnel Training (Grant No. J1103210)the Youth Science Foundation of Shanxi Province of China (Grant No. 2010021003-2)
文摘In this work we investigated the geometric phases of a qubit-oscillator system beyond the conventional rotating- wave approximation. We find that in the limiting of weak coupling the results coincide with that obtained under rotating-wave approximation while there exists an increasing difference with the increase of coupling constant. It was shown that the geometric phase is symmetric with respect to the sign of the detuning of the quantized field from the one-photon resonance under the conventional rotating-wave approximation while a red-blue detuning asymmetry occurs beyond the conventional rotating-wave approximation.
基金the Special Foundation for theoretical physics Research Program of China (Grant No. 11647165)the China Postdoctoral Science Foundation Funded Project (Project No. 2020M673118)+3 种基金the funding from the National Natural Science Foundation of China (Grant No. 11874247)the National Key Research and Development Program of China (Grant No. 2017YFA0304500)the Program of State Key Laboratory of Quantum Optics and Quantum Optics Devices, China (Grant No. KF201703)the support from Guangdong Provincial Key Laboratory (Grant No. 2019B121203002)。
文摘We study theoretically the nonadiabatic geometric phase of a doubly driven two-level system with an additional relative phase between the two driving modes introduced in. It is shown that the time evolution of the system strongly depends on this relative phase. The condition for the system returning to its initial state after a single period is given by the means of the Landau–Zener–Stückelberg–Majorana destructive interference. The nonadiabatic geometric phase accompanying a cyclic evolution is shown to be related to the Stokes phase as well as this relative phase. By controlling the relative phase, the geometric phase can characterize two distinct phases in the adiabatic limit.
基金The project supported by National Natural Science Foundation of China under Grant No.60573008
文摘We analyze the effect of stochastic dephasing on geometric phases. The result implies that the correction of geometric phases relies on not only the fluctuation of the random variable in the stochastic process, but also the frequency of the system.
