A two-dimensional （2D） full band self-consistent ensemble Monte Carlo （MC） method for solving the quantum Boltzmann equation, including collision broadening and quantum potential corrections, is developed to exten...A two-dimensional （2D） full band self-consistent ensemble Monte Carlo （MC） method for solving the quantum Boltzmann equation, including collision broadening and quantum potential corrections, is developed to extend the MC method to the study of nano-scale semiconductor devices with obvious quantum mechanical （QM） effects. The quantum effects both in real space and momentum space in nano-scale semiconductor devices can be simulated. The effective mobility in the inversion layer of n and p channel MOSFET is simulated and compared with experimental data to verify this method. With this method 50nm ultra thin body silicon on insulator MOSFET are simulated. Results indicate that this method can be used to simulate the 2D QM effects in semiconductor devices including tunnelling effect.展开更多
Nature at the lab level in biology and chemistry can be described by the application of quantum mechanics.In many cases,a reasonable approximation to quantum mechanics is classical mechanics realized through Newton...Nature at the lab level in biology and chemistry can be described by the application of quantum mechanics.In many cases,a reasonable approximation to quantum mechanics is classical mechanics realized through Newton's equations of motion.Dr.Pedersen began his career using quantum mechanics to describe the properties of small molecular complexes that could serve as models for biochemical systems.To describe large molecular systems required a drop-back to classical means and this led surprisingly to a major improvement in the classical treatment of electrostatics for all molecules,not just biological molecules.Recent work has involved the application of quantum mechanics for the putative active sites of enzymes to gain greater insight into the key steps in enzyme catalysis.展开更多
Preliminary results of a study are reported here investigating mesoscopic tunnel junctions irradiated with coherent low-intensity (-50 to -10 dB) pulsed microwave RF fields at moderately low (LN2) temperatures. Quantu...Preliminary results of a study are reported here investigating mesoscopic tunnel junctions irradiated with coherent low-intensity (-50 to -10 dB) pulsed microwave RF fields at moderately low (LN2) temperatures. Quantum tunneling of electrons was observed through fabricated mesoscale gap junctions as a result of coherent irradiating fields at low temperatures around 77 - 100 K. The tunneling current was seen as a result of applied microwave fields across the junctions, distinguishable from shot noise and resistance effects. The form of tunneling behavior does not lead to any conductance quantization effects which could manifest the junction as a Quantum Point Contact (QPC), hence it is surmised that the phenomenon is purely low intensity RF field-induced tunneling of electrons across the mesoscale junctions at low temperatures.展开更多
According to quantum mechanics, the outcome of an experiment exists relative to an Experimenter who performs a measurement on the system under study. Witnessing the outcome of an experience requires the measurement on...According to quantum mechanics, the outcome of an experiment exists relative to an Experimenter who performs a measurement on the system under study. Witnessing the outcome of an experience requires the measurement on a physical system whose size must match the complexity of the Experimenter’s observation. We argue that such a physical system must have a certain space-time extension so that it can encode the rich and complex data embedded in the witnessed experience. The complementarity principle in quantum mechanics leads us to conjecture that the observable events constituting an experience have space-like separation with each other. This seems to be in contradiction with our perceived locality of physical laws, and encourages us to think that the act of measurement is not a physical process, in the sense that a measurement outcome witnessed by an Experimenter is not necessarily related to the physical description of the Experimenter observed from the outside.展开更多
By virtue of the completeness of Wigner operator and Weyl correspondence we construct a general equation for deriving pure state density operators. Several important examples are considered as the applications of this...By virtue of the completeness of Wigner operator and Weyl correspondence we construct a general equation for deriving pure state density operators. Several important examples are considered as the applications of this equation, which shows that our approach is effective and convenient for deducing these entangled state representations.展开更多
A physics-based analytical model for symmetrically biased double-gate（DG） MOSFETs considering quantum mechanical effects is proposed.Schrodinger＇s and Poisson＇s equations are solved simultaneously using a variatio...A physics-based analytical model for symmetrically biased double-gate（DG） MOSFETs considering quantum mechanical effects is proposed.Schrodinger＇s and Poisson＇s equations are solved simultaneously using a variational approach.Solving the Poisson and Schrodinger equations simultaneously reveals quantum mechanical effects（QME） that influence the performance of DG MOSFETs.The inversion charge and electrical potential distributions perpendicular to the channel are expressed in closed forms.We systematically evaluated and analyzed the potentials and inversion charges,taking QME into consideration,in Si based double gate devices.The effect of silicon thickness variation in inversion-layer charge and potentials are quantitatively defined.The analytical solutions provide good physical insight into the quantization caused by quantum confinement under various gate biases.展开更多
The organic/inorganic hybrid nanostructural vinylsilsesquioxanes (VSSO) were prepared from the hydrolytic condensation of vinyltrimethoxysilane (VMS). The proposed formu- las of VSSO were assigned with standard spectr...The organic/inorganic hybrid nanostructural vinylsilsesquioxanes (VSSO) were prepared from the hydrolytic condensation of vinyltrimethoxysilane (VMS). The proposed formu- las of VSSO were assigned with standard spectroscopic techniques, FTIR, NMR (1H, C and 13 29Si) and MALDI-TOF MS, and a generic formula of the SSO, Tn(OH)x(OR’)y(x, y = 0, 1, 2…; n = 1, 2…; T = RSiO1.5 ?(x+y)/2n). Geometric parameters (Si-O and Si-C bond lengths, Si-O-Si and O-Si-O bond angles) and total energies of the multi-structures of VSSO were calculated by a quantum mechanical investigation and molecular symmetries. According to the results of the calculation, most molecules had stabler ladder structures than the cage isomers, therefore, the most probably reasonable and optimum structure of the VSSO system was the ladder type.展开更多
Sub-10-nm bulk n-MOSFET （metal-oxide -semiconductor field effect transistor） direct source-to- drain tunneling current density using Wentzel- Krammers-Brillouin 0NKB） transmission tunneling theory has been simulate...Sub-10-nm bulk n-MOSFET （metal-oxide -semiconductor field effect transistor） direct source-to- drain tunneling current density using Wentzel- Krammers-Brillouin 0NKB） transmission tunneling theory has been simulated. The dependence of the source-to-drain tunneling current on channel length and barrier height is examined. Inversion layer quantization, band-gap narrowing, and drain induced barrier lowering effects have been included in the model. It has been observed that the leakage current density increases severely below 4 nm channel lengths, thus putting a limit to the scaling down of the MOSFETs. The results match closely with the numerical results already reported in literatures.展开更多
The important features of the low-lying states of C are obtained via an analysis of quantum mechanical symmetry. The existence of a 4 state lower than the 4] state is found to be essential to judging the validity of t...The important features of the low-lying states of C are obtained via an analysis of quantum mechanical symmetry. The existence of a 4 state lower than the 4] state is found to be essential to judging the validity of the Set model of 12C. It is pointed out that the states can be candidates of the linear chain structure.展开更多
基金Project supported by the Special Foundation for State Major Basic Research Program of China （Grant No G2000035602） and the National Natural Science Foundation of China （Grant No 90307006）.
文摘A two-dimensional （2D） full band self-consistent ensemble Monte Carlo （MC） method for solving the quantum Boltzmann equation, including collision broadening and quantum potential corrections, is developed to extend the MC method to the study of nano-scale semiconductor devices with obvious quantum mechanical （QM） effects. The quantum effects both in real space and momentum space in nano-scale semiconductor devices can be simulated. The effective mobility in the inversion layer of n and p channel MOSFET is simulated and compared with experimental data to verify this method. With this method 50nm ultra thin body silicon on insulator MOSFET are simulated. Results indicate that this method can be used to simulate the 2D QM effects in semiconductor devices including tunnelling effect.
基金Supported by The National Institutes of Health (HL-006350)National Science Foundation (FRG DMR 0804549)
文摘Nature at the lab level in biology and chemistry can be described by the application of quantum mechanics.In many cases,a reasonable approximation to quantum mechanics is classical mechanics realized through Newton's equations of motion.Dr.Pedersen began his career using quantum mechanics to describe the properties of small molecular complexes that could serve as models for biochemical systems.To describe large molecular systems required a drop-back to classical means and this led surprisingly to a major improvement in the classical treatment of electrostatics for all molecules,not just biological molecules.Recent work has involved the application of quantum mechanics for the putative active sites of enzymes to gain greater insight into the key steps in enzyme catalysis.
文摘Preliminary results of a study are reported here investigating mesoscopic tunnel junctions irradiated with coherent low-intensity (-50 to -10 dB) pulsed microwave RF fields at moderately low (LN2) temperatures. Quantum tunneling of electrons was observed through fabricated mesoscale gap junctions as a result of coherent irradiating fields at low temperatures around 77 - 100 K. The tunneling current was seen as a result of applied microwave fields across the junctions, distinguishable from shot noise and resistance effects. The form of tunneling behavior does not lead to any conductance quantization effects which could manifest the junction as a Quantum Point Contact (QPC), hence it is surmised that the phenomenon is purely low intensity RF field-induced tunneling of electrons across the mesoscale junctions at low temperatures.
文摘According to quantum mechanics, the outcome of an experiment exists relative to an Experimenter who performs a measurement on the system under study. Witnessing the outcome of an experience requires the measurement on a physical system whose size must match the complexity of the Experimenter’s observation. We argue that such a physical system must have a certain space-time extension so that it can encode the rich and complex data embedded in the witnessed experience. The complementarity principle in quantum mechanics leads us to conjecture that the observable events constituting an experience have space-like separation with each other. This seems to be in contradiction with our perceived locality of physical laws, and encourages us to think that the act of measurement is not a physical process, in the sense that a measurement outcome witnessed by an Experimenter is not necessarily related to the physical description of the Experimenter observed from the outside.
基金supported by the National Natural Science Foundation of China (Grant Nos. 10874174 and 90203002)
文摘By virtue of the completeness of Wigner operator and Weyl correspondence we construct a general equation for deriving pure state density operators. Several important examples are considered as the applications of this equation, which shows that our approach is effective and convenient for deducing these entangled state representations.
文摘A physics-based analytical model for symmetrically biased double-gate（DG） MOSFETs considering quantum mechanical effects is proposed.Schrodinger＇s and Poisson＇s equations are solved simultaneously using a variational approach.Solving the Poisson and Schrodinger equations simultaneously reveals quantum mechanical effects（QME） that influence the performance of DG MOSFETs.The inversion charge and electrical potential distributions perpendicular to the channel are expressed in closed forms.We systematically evaluated and analyzed the potentials and inversion charges,taking QME into consideration,in Si based double gate devices.The effect of silicon thickness variation in inversion-layer charge and potentials are quantitatively defined.The analytical solutions provide good physical insight into the quantization caused by quantum confinement under various gate biases.
文摘The organic/inorganic hybrid nanostructural vinylsilsesquioxanes (VSSO) were prepared from the hydrolytic condensation of vinyltrimethoxysilane (VMS). The proposed formu- las of VSSO were assigned with standard spectroscopic techniques, FTIR, NMR (1H, C and 13 29Si) and MALDI-TOF MS, and a generic formula of the SSO, Tn(OH)x(OR’)y(x, y = 0, 1, 2…; n = 1, 2…; T = RSiO1.5 ?(x+y)/2n). Geometric parameters (Si-O and Si-C bond lengths, Si-O-Si and O-Si-O bond angles) and total energies of the multi-structures of VSSO were calculated by a quantum mechanical investigation and molecular symmetries. According to the results of the calculation, most molecules had stabler ladder structures than the cage isomers, therefore, the most probably reasonable and optimum structure of the VSSO system was the ladder type.
文摘Sub-10-nm bulk n-MOSFET （metal-oxide -semiconductor field effect transistor） direct source-to- drain tunneling current density using Wentzel- Krammers-Brillouin 0NKB） transmission tunneling theory has been simulated. The dependence of the source-to-drain tunneling current on channel length and barrier height is examined. Inversion layer quantization, band-gap narrowing, and drain induced barrier lowering effects have been included in the model. It has been observed that the leakage current density increases severely below 4 nm channel lengths, thus putting a limit to the scaling down of the MOSFETs. The results match closely with the numerical results already reported in literatures.
基金Project supprted by the National Natural Science Foundation of China and the Natural Science Foundation of Guangdong Province.
文摘The important features of the low-lying states of C are obtained via an analysis of quantum mechanical symmetry. The existence of a 4 state lower than the 4] state is found to be essential to judging the validity of the Set model of 12C. It is pointed out that the states can be candidates of the linear chain structure.
