This paper shows that a proposal for implementing all possible two-operator positive-operator-value measurements of single spin qubit can be obtained via introducing another spin qubit as ancilla. The realization proc...This paper shows that a proposal for implementing all possible two-operator positive-operator-value measurements of single spin qubit can be obtained via introducing another spin qubit as ancilla. The realization process is accomplished from the free evolution of the Heisenberg XX model by considering nearest-neighbour spin interaction. A controlled- NOT gate, which is a significant operator for this scheme is also constructed and the generalisation to multiple-operator is considered finally.展开更多
A novel roof tile thermoelectric generator(RT-TEG)was used to harvest electrical energy from a solar heat source.The RT-TEG was fabricated and simulated by flat and curved thermoelectric modules consisting of p-n junc...A novel roof tile thermoelectric generator(RT-TEG)was used to harvest electrical energy from a solar heat source.The RT-TEG was fabricated and simulated by flat and curved thermoelectric modules consisting of p-n junctions of p-Sb_(2)Te_(3) and n-Bi_(2)Te_(3),with an Al_(2)O_(3) substrate at the top and bottom for heat absorption and heat rejection.The RT-TEG was installed in a roof tile to act as a generator.The electrical voltage and power values of the curved thermoelectric modules were higher than those of the flat thermoelectric module by 0.44 V and 80 mW,at a temperature difference(ΔT)of 100 K.In field tests,the RT-TEG produced a maximum electrical voltage of 33.70 mV and an electrical power of 46.24μW atΔT~7 K under a load resistance of 1Ωunder good sunshine at 13.00 hours.The energy conversion efficiency of RT-TEG was found to be 2.24×10^(−4).展开更多
The thin films were deposited on the glass substrates by an asymmetric bipolar pulsed-dc magnetron sputtering system using the Ca3Co4O9 and CaMnO3 Targets (n-type) targets of 60 mm diameter and 2.5 mm thickness. The t...The thin films were deposited on the glass substrates by an asymmetric bipolar pulsed-dc magnetron sputtering system using the Ca3Co4O9 and CaMnO3 Targets (n-type) targets of 60 mm diameter and 2.5 mm thickness. The targets were prepared from powder precursors, which obtained by a solid state reaction. Optical emissions from plasmas during sputter depositions of films were detected using a high resolution spectrometer. Thickness of thin film was estimated by Tolansky’s Fizeau fringe method and ellipsometic measurement. Crystal structures were studied from X-ray diffraction. The thermoelectric properties were assessed from Seebeck coefficient and electrical resistivity measurements at room temperature. The power factors were calculated. It was found that the optical emission spectrums showed that the Ca, Mn, Co and O atoms were sputtered from the targets onto glass substrates. As-deposited Ca-Co-O and Ca-Mn-O films thickness values were 0.435 ?m and 0.449 ?m, respectively. The X-ray diffraction patterns clearly showed amorphous nature of the as-deposited films. Determining thermoelectric properties of Ca-Co-O film gave Seebeck coefficient of 0.146 mV/K, electrical resistivity of 0.473Ω.cm, and power factor of 4.531 μW/m?K at room temperature. Ca-Mn-O film baring a high resistance was not the experimental determination of thermoelectric properties.展开更多
This paper investigates the concept of Cross Polarization (CP) experiment in addition to revisiting the two potential expansion schemes recently developed in the field of solid-state nuclear magnetic resonance (SSNMR)...This paper investigates the concept of Cross Polarization (CP) experiment in addition to revisiting the two potential expansion schemes recently developed in the field of solid-state nuclear magnetic resonance (SSNMR): namely, the Floquet-Magnus expansion and the Fer expansion. We use the aforementioned expansion schemes for the calculation of effective Hamiltonians and propagators when the spin system undergoes Cross Polarization radiation. CP is the gateway experiment into SSNMR. An in-depth comprehension of the underlying mechanics of spin dynamics during the cross-polarization experiment is pivotal for further experimental developments and optimization of more complex solid-state NMR experiments. The main contribution of this work is a prospect related to spin physics;particularly regarding to generalization of the calculation. This work reports original yet interesting novel ideas and developments that include calculations performed on the CP experiment. In fact, the approach presented could play a major role in the interpretation of several fine NMR experiments in solids, which would in turn provide significant new insights in spin physics. The generality of the work points towards potential applications in problems related in solid-state NMR and theoretical developments of spectroscopy as well as interdisciplinary research areas as long as they include spin dynamics concepts.展开更多
Dear Editor,Paper wasps have been the subject of numerous studies across various disciplines,including biology(Grinsted&Field,2017),ecology(Sheehan et al.,2015),chemistry(Cini et al.,2011),and physics(Chawla et al...Dear Editor,Paper wasps have been the subject of numerous studies across various disciplines,including biology(Grinsted&Field,2017),ecology(Sheehan et al.,2015),chemistry(Cini et al.,2011),and physics(Chawla et al.,2020).Previous research has primarily focused on their behavior from biological and ecological perspectives.However,recent investigations from a physics standpoint have also explored their nesting behavior,including the use of defensive structures.展开更多
We propose a multi-bit dense coding scheme by using only an Einstein-Podolsky-Rosen（EPR） channel and assistant qubits.It is shown that no matter how many classical bits there are,the quantum channel is always a Bell...We propose a multi-bit dense coding scheme by using only an Einstein-Podolsky-Rosen（EPR） channel and assistant qubits.It is shown that no matter how many classical bits there are,the quantum channel is always a Bell state.The present dense coding process can also prepare non-local multi-particle Greenberger-Horne-Zeilinger（GHZ） states at one of the participants.The quantum circuits for this dense coding process are constructed,the deterministic implementation method in an optical system based on the cross-Kerr nonlinearities is shown.展开更多
Bismuth antimony telluride(Bi_(2–x)Sb_(x)Te_(3))is commonly used for thermoelectric generation at temperatures near ambient temperature.Here,we report incorporating reduced graphene oxide(rGO)and Cu_(2)Se_(0.98)Te_(0...Bismuth antimony telluride(Bi_(2–x)Sb_(x)Te_(3))is commonly used for thermoelectric generation at temperatures near ambient temperature.Here,we report incorporating reduced graphene oxide(rGO)and Cu_(2)Se_(0.98)Te_(0.02) into the Bi_(0.5)Sb_(1.5)Te_(3)(BST)(rGO/Bi_(0.5)Sb_(1.5)Te_(3-x)Cu_(2)Se_(0.98)Te_(0.02),where x=0.0%,0.1%,0.3%,0.5% and 1.0%,in mass)synthesized by a solid-state technique.The dispersion of rGO and Cu_(2)Se_(0.98)Te_(0.02) into the BST matrix improved carrier transport properties at the grain boundary interfaces and reduced thermal conductivity.Strong electron scattering at large interface barriers was responsible for increased electrical conductivity.The bulk sample of rGO/BST-0.3%Cu_(2)Se_(0.98)Te_(0.02)(in mass)possessed a low thermal conductivity of 0.76 W·m^(−1)·K^(−1) at 497 K.Enhanced phonon scattering at grain boundaries between BST and rGO/Cu_(2)Se_(0.98)Te_(0.02) caused a low thermal conductivity.At 448 K,the highest zT value for rGO/BST-0.3% Cu_(2)Se_(0.98)Te_(0.02)(in mass)was 1.64,which is 37% higher than the zT value for pure BST(zT=1.19).Results suggested that incorporating rGO and Cu_(2)Se_(0.98)Te_(0.02) into the BST matrix effectively improved thermoelectric power generation.展开更多
基金supported by the National Natural Science Foundation of China (Grant No.60667001)
文摘This paper shows that a proposal for implementing all possible two-operator positive-operator-value measurements of single spin qubit can be obtained via introducing another spin qubit as ancilla. The realization process is accomplished from the free evolution of the Heisenberg XX model by considering nearest-neighbour spin interaction. A controlled- NOT gate, which is a significant operator for this scheme is also constructed and the generalisation to multiple-operator is considered finally.
基金supported by the Thailand Research Fund(TRF)Research Career Development Grant:(RSA6180070).
文摘A novel roof tile thermoelectric generator(RT-TEG)was used to harvest electrical energy from a solar heat source.The RT-TEG was fabricated and simulated by flat and curved thermoelectric modules consisting of p-n junctions of p-Sb_(2)Te_(3) and n-Bi_(2)Te_(3),with an Al_(2)O_(3) substrate at the top and bottom for heat absorption and heat rejection.The RT-TEG was installed in a roof tile to act as a generator.The electrical voltage and power values of the curved thermoelectric modules were higher than those of the flat thermoelectric module by 0.44 V and 80 mW,at a temperature difference(ΔT)of 100 K.In field tests,the RT-TEG produced a maximum electrical voltage of 33.70 mV and an electrical power of 46.24μW atΔT~7 K under a load resistance of 1Ωunder good sunshine at 13.00 hours.The energy conversion efficiency of RT-TEG was found to be 2.24×10^(−4).
文摘The thin films were deposited on the glass substrates by an asymmetric bipolar pulsed-dc magnetron sputtering system using the Ca3Co4O9 and CaMnO3 Targets (n-type) targets of 60 mm diameter and 2.5 mm thickness. The targets were prepared from powder precursors, which obtained by a solid state reaction. Optical emissions from plasmas during sputter depositions of films were detected using a high resolution spectrometer. Thickness of thin film was estimated by Tolansky’s Fizeau fringe method and ellipsometic measurement. Crystal structures were studied from X-ray diffraction. The thermoelectric properties were assessed from Seebeck coefficient and electrical resistivity measurements at room temperature. The power factors were calculated. It was found that the optical emission spectrums showed that the Ca, Mn, Co and O atoms were sputtered from the targets onto glass substrates. As-deposited Ca-Co-O and Ca-Mn-O films thickness values were 0.435 ?m and 0.449 ?m, respectively. The X-ray diffraction patterns clearly showed amorphous nature of the as-deposited films. Determining thermoelectric properties of Ca-Co-O film gave Seebeck coefficient of 0.146 mV/K, electrical resistivity of 0.473Ω.cm, and power factor of 4.531 μW/m?K at room temperature. Ca-Mn-O film baring a high resistance was not the experimental determination of thermoelectric properties.
文摘This paper investigates the concept of Cross Polarization (CP) experiment in addition to revisiting the two potential expansion schemes recently developed in the field of solid-state nuclear magnetic resonance (SSNMR): namely, the Floquet-Magnus expansion and the Fer expansion. We use the aforementioned expansion schemes for the calculation of effective Hamiltonians and propagators when the spin system undergoes Cross Polarization radiation. CP is the gateway experiment into SSNMR. An in-depth comprehension of the underlying mechanics of spin dynamics during the cross-polarization experiment is pivotal for further experimental developments and optimization of more complex solid-state NMR experiments. The main contribution of this work is a prospect related to spin physics;particularly regarding to generalization of the calculation. This work reports original yet interesting novel ideas and developments that include calculations performed on the CP experiment. In fact, the approach presented could play a major role in the interpretation of several fine NMR experiments in solids, which would in turn provide significant new insights in spin physics. The generality of the work points towards potential applications in problems related in solid-state NMR and theoretical developments of spectroscopy as well as interdisciplinary research areas as long as they include spin dynamics concepts.
文摘Dear Editor,Paper wasps have been the subject of numerous studies across various disciplines,including biology(Grinsted&Field,2017),ecology(Sheehan et al.,2015),chemistry(Cini et al.,2011),and physics(Chawla et al.,2020).Previous research has primarily focused on their behavior from biological and ecological perspectives.However,recent investigations from a physics standpoint have also explored their nesting behavior,including the use of defensive structures.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 61068001 and 11147174)
文摘We propose a multi-bit dense coding scheme by using only an Einstein-Podolsky-Rosen（EPR） channel and assistant qubits.It is shown that no matter how many classical bits there are,the quantum channel is always a Bell state.The present dense coding process can also prepare non-local multi-particle Greenberger-Horne-Zeilinger（GHZ） states at one of the participants.The quantum circuits for this dense coding process are constructed,the deterministic implementation method in an optical system based on the cross-Kerr nonlinearities is shown.
基金This research has received funding support from the National Science,Research and Innovation Fund(NSRF)via the Program Management Unit for Human Resources&Institutional Development,Research and Innovation[grant number B05F640150],Thailand.
文摘Bismuth antimony telluride(Bi_(2–x)Sb_(x)Te_(3))is commonly used for thermoelectric generation at temperatures near ambient temperature.Here,we report incorporating reduced graphene oxide(rGO)and Cu_(2)Se_(0.98)Te_(0.02) into the Bi_(0.5)Sb_(1.5)Te_(3)(BST)(rGO/Bi_(0.5)Sb_(1.5)Te_(3-x)Cu_(2)Se_(0.98)Te_(0.02),where x=0.0%,0.1%,0.3%,0.5% and 1.0%,in mass)synthesized by a solid-state technique.The dispersion of rGO and Cu_(2)Se_(0.98)Te_(0.02) into the BST matrix improved carrier transport properties at the grain boundary interfaces and reduced thermal conductivity.Strong electron scattering at large interface barriers was responsible for increased electrical conductivity.The bulk sample of rGO/BST-0.3%Cu_(2)Se_(0.98)Te_(0.02)(in mass)possessed a low thermal conductivity of 0.76 W·m^(−1)·K^(−1) at 497 K.Enhanced phonon scattering at grain boundaries between BST and rGO/Cu_(2)Se_(0.98)Te_(0.02) caused a low thermal conductivity.At 448 K,the highest zT value for rGO/BST-0.3% Cu_(2)Se_(0.98)Te_(0.02)(in mass)was 1.64,which is 37% higher than the zT value for pure BST(zT=1.19).Results suggested that incorporating rGO and Cu_(2)Se_(0.98)Te_(0.02) into the BST matrix effectively improved thermoelectric power generation.
