In this paper, we give the most general duality gates, or generalized quantum gates in duality quantum computers. Here we show by explicit construction that a n-bit duality quantum computer with d slits can be simulat...In this paper, we give the most general duality gates, or generalized quantum gates in duality quantum computers. Here we show by explicit construction that a n-bit duality quantum computer with d slits can be simulated perfectly with an ordinary quantum computer with n qubits and one auxiliary qudit. Using this model, we give the most general form of duality gates which is of the form ∑i=0^d-1piUi,and the pi 's are complex numbers with module less or equal to 1 and constrained by|∑iPi|≤1.展开更多
We derive normally ordered quantum gate operators for continuum variables by mapping classical transforms onto Fock space. Successive gate operations can be treated in a unified way that is using the technique of inte...We derive normally ordered quantum gate operators for continuum variables by mapping classical transforms onto Fock space. Successive gate operations can be treated in a unified way that is using the technique of integration within an ordered product of operators.展开更多
We propose a method of controlling the dc-SQUID (superconducting quantum interference device) system by changing the gate voltages, which controls the amplitude of the fictitious magnetic fields B-z, and the externall...We propose a method of controlling the dc-SQUID (superconducting quantum interference device) system by changing the gate voltages, which controls the amplitude of the fictitious magnetic fields B-z, and the externally applied current that produces the piercing magnetic flux Phi(x) for the dc-SQUID system. We have also introduced a physical model for the dc-SQUID system. Using this physical model, one can obtain the non-adiabatic geometric phase gate for the single qubit and the non-adiabatic conditional geometric phase gate (controlled NOT gate) for the two qubits. It is shown that when the gate voltage and the externally applied current of the dc-SQUID system satisfies an appropriate constraint condition, the charge state evolution can be controlled exactly on a dynamic phase free path. The non-adiabatic evolution of the charge states is given as well.展开更多
In this letter, by using the method we offered in our paper [L. Ma and Y.D. Zhang, Commun. Theor. Phys.(Beijing, China) 36 (2001) 119], some extended quantum logic gates, such as quantum counter, quantum adder, are st...In this letter, by using the method we offered in our paper [L. Ma and Y.D. Zhang, Commun. Theor. Phys.(Beijing, China) 36 (2001) 119], some extended quantum logic gates, such as quantum counter, quantum adder, are studied and their expressions are given. It may be useful for us to study the more complicated quantum logic circuits deeply.展开更多
The priority of the EU transport policy in railway sector is to open up the railway market. The objective is to provide railway undertakings with access to the railway network on equal terms. The main problem is deter...The priority of the EU transport policy in railway sector is to open up the railway market. The objective is to provide railway undertakings with access to the railway network on equal terms. The main problem is determining the infrastructure capacity. A variety of methodologies are used across Europe for the capacity estimation of railway infrastructure. This diversity has forced railway infrastructure managers to seek a new, common methodology. The UIC methodology is an easy way to calculate the capacity consumption. However, there the possibility to expound this methodology in different ways, which can result in different capacity consumptions. There isan advantage to improve this methodology and to set a clear and unified method of occupation time estimation. The fundamental improvement to UIC methodology is the definition of the occupation time by the trains. This paper gives a description of Slovak and UIC methodologies as a basis for a newly developed approach. The new way of estimation of the capacity consumption (occupation time) is based on a graphic approach. The new methodology concerns the estimation of the infrastructure occupation time and is a conceptual framework developed by the authors for an easier evaluation of occupation time in train traffic diagrams. The new methodology makes the UIC methodology more usable and enables more exact results to be obtained from infrastructure capacity examination.展开更多
Anyons can be used to realize quantum computation, because they are two-level systems in two dimensions. In this paper, we propose a scheme to simulate single-qubit gates and CNOT gate using Abelian anyons in the Kita...Anyons can be used to realize quantum computation, because they are two-level systems in two dimensions. In this paper, we propose a scheme to simulate single-qubit gates and CNOT gate using Abelian anyons in the Kitaev model. Two pairs of anyons (six spins) are used to realize single-qubit gates, while ten spins are needed for the CNOT gate. Based on these quantum gates, we show how to realize the Grover algorithm in a two-qubit system.展开更多
We propose a simple and fast scheme to realize a controlled-NOT gate between two trapped ions using a resonant laser pulse. Our scheme allows the Rabi frequency of the laser field to be of the order of the vibrational...We propose a simple and fast scheme to realize a controlled-NOT gate between two trapped ions using a resonant laser pulse. Our scheme allows the Rabi frequency of the laser field to be of the order of the vibrational frequency and thus the time required to complete the operation is greatly shortened, which is of importance in view of decoherence.展开更多
We investigate the effects of noisy quantum channels on the entanglement of cluster states and one way quantum computational gates.We take a basic model,the rotational gate about x axis based on the cluster state,in o...We investigate the effects of noisy quantum channels on the entanglement of cluster states and one way quantum computational gates.We take a basic model,the rotational gate about x axis based on the cluster state,in order to get the most essential effects of the paradigmatic noisy quantum channels.The entanglement of cluster states in the noisy channels and the fidelity between the rotated state without noisy channel and that with noisy channel are calculated.展开更多
Traditional CMOS technology faces some fundamental physical limitations. Therefore, it has become very important for the integrated circuit industry to continue to develop modem devices and new design methods. The thr...Traditional CMOS technology faces some fundamental physical limitations. Therefore, it has become very important for the integrated circuit industry to continue to develop modem devices and new design methods. The threshold logic gate has attracted much attention because of its powerful logic function. The resonant tunneling diode (RTD) is well suited for imple- menting the threshold logic gate because of its high-speed switching capability, negative differential resistance (NDR) charac- teristic, and functional versatility. In this paper, based on the Reed-Muller (RM) algebraic system, a novel method is proposed to convert three-variable non-threshold functions to the XOR of multiple threshold functions, which is simple and has a program- mable implementation. With this approach, all three-variable non-threshold functions can be presented by the XOR of two threshold functions, except for two special functions. On this basis, a novel three-variable universal logic gate (ULG3) is proposed, composed of two RTD-based universal threshold logic gates (UTLG) and an RTD-based three-variable XOR gate (XOR3). The ULG3 has a simple structure, and a simple method is presented to implement all three-variable functions using one ULG3. Thus, the proposed ULG3 provides a new efficient universal logic gate to implement RTD-based arbitrary n-variable functions.展开更多
Stark-chirped rapid adiabatic passage(SCRAP) is an important technique used for coherent quantum controls. In this paper we investigate how the practically-existing dissipation of the system influences on the efficien...Stark-chirped rapid adiabatic passage(SCRAP) is an important technique used for coherent quantum controls. In this paper we investigate how the practically-existing dissipation of the system influences on the efficiency of the passage, and thus the fidelities of the SCRAP-based quantum gates. With flux-biased Josephson qubits as a specifical example, our results show clearly that the efficiency of the logic gates implemented by SCRAP are robust against the weak dissipation. The influence due to the non-adiabtic transitions between the adiabatic passages is comparatively significantly small. Therefore, the SCRAP-based logic gates should be feasible for the realistic physical systems with noises.展开更多
Rural work conference maps out reform plans toimprove China's agriculture industryChina hopes to reform its agriculture sector this year to increase food produce quality,reduce the grain oversupply and help rural pop...Rural work conference maps out reform plans toimprove China's agriculture industryChina hopes to reform its agriculture sector this year to increase food produce quality,reduce the grain oversupply and help rural populations living in poverty achieve prosperity.The plan was laid out at the end of December of last year when Chinese leaders held a central rural work conference to review how the agriculture industry performed in 2015展开更多
基金supported by the National Fundamental Research Program Grant Nos.2006CB921106, 2009CB929042National Natural Science Foundation of China under Grant Nos. 10874098, 10775076, and 60433050
文摘In this paper, we give the most general duality gates, or generalized quantum gates in duality quantum computers. Here we show by explicit construction that a n-bit duality quantum computer with d slits can be simulated perfectly with an ordinary quantum computer with n qubits and one auxiliary qudit. Using this model, we give the most general form of duality gates which is of the form ∑i=0^d-1piUi,and the pi 's are complex numbers with module less or equal to 1 and constrained by|∑iPi|≤1.
文摘We derive normally ordered quantum gate operators for continuum variables by mapping classical transforms onto Fock space. Successive gate operations can be treated in a unified way that is using the technique of integration within an ordered product of operators.
文摘We propose a method of controlling the dc-SQUID (superconducting quantum interference device) system by changing the gate voltages, which controls the amplitude of the fictitious magnetic fields B-z, and the externally applied current that produces the piercing magnetic flux Phi(x) for the dc-SQUID system. We have also introduced a physical model for the dc-SQUID system. Using this physical model, one can obtain the non-adiabatic geometric phase gate for the single qubit and the non-adiabatic conditional geometric phase gate (controlled NOT gate) for the two qubits. It is shown that when the gate voltage and the externally applied current of the dc-SQUID system satisfies an appropriate constraint condition, the charge state evolution can be controlled exactly on a dynamic phase free path. The non-adiabatic evolution of the charge states is given as well.
文摘In this letter, by using the method we offered in our paper [L. Ma and Y.D. Zhang, Commun. Theor. Phys.(Beijing, China) 36 (2001) 119], some extended quantum logic gates, such as quantum counter, quantum adder, are studied and their expressions are given. It may be useful for us to study the more complicated quantum logic circuits deeply.
文摘The priority of the EU transport policy in railway sector is to open up the railway market. The objective is to provide railway undertakings with access to the railway network on equal terms. The main problem is determining the infrastructure capacity. A variety of methodologies are used across Europe for the capacity estimation of railway infrastructure. This diversity has forced railway infrastructure managers to seek a new, common methodology. The UIC methodology is an easy way to calculate the capacity consumption. However, there the possibility to expound this methodology in different ways, which can result in different capacity consumptions. There isan advantage to improve this methodology and to set a clear and unified method of occupation time estimation. The fundamental improvement to UIC methodology is the definition of the occupation time by the trains. This paper gives a description of Slovak and UIC methodologies as a basis for a newly developed approach. The new way of estimation of the capacity consumption (occupation time) is based on a graphic approach. The new methodology concerns the estimation of the infrastructure occupation time and is a conceptual framework developed by the authors for an easier evaluation of occupation time in train traffic diagrams. The new methodology makes the UIC methodology more usable and enables more exact results to be obtained from infrastructure capacity examination.
基金Supported by the National Natural Science Foundation of China under Grant No. 10874098the National Basic Research Program of China under Grant Nos. 2009CB929402, 2011CB9216002the Specialized Research Fund for the Doctoral Program of Education Ministry of China under Grant No. 20060003048
文摘Anyons can be used to realize quantum computation, because they are two-level systems in two dimensions. In this paper, we propose a scheme to simulate single-qubit gates and CNOT gate using Abelian anyons in the Kitaev model. Two pairs of anyons (six spins) are used to realize single-qubit gates, while ten spins are needed for the CNOT gate. Based on these quantum gates, we show how to realize the Grover algorithm in a two-qubit system.
基金The project supported by Fok Ying Tung Education Foundation under Grant No.81008+4 种基金National Natural Science Foundation of China under Grant No.60008003Natural Science Foundation of Fujian Province of China under Grant Nos.K20004 and F0110027the Funds from Fuzhou University
文摘We propose a simple and fast scheme to realize a controlled-NOT gate between two trapped ions using a resonant laser pulse. Our scheme allows the Rabi frequency of the laser field to be of the order of the vibrational frequency and thus the time required to complete the operation is greatly shortened, which is of importance in view of decoherence.
基金supported by the National Natural Science Foundation of China (Grant No.11175105)the National Research Foundation&Ministry of Education,Singapore
文摘We investigate the effects of noisy quantum channels on the entanglement of cluster states and one way quantum computational gates.We take a basic model,the rotational gate about x axis based on the cluster state,in order to get the most essential effects of the paradigmatic noisy quantum channels.The entanglement of cluster states in the noisy channels and the fidelity between the rotated state without noisy channel and that with noisy channel are calculated.
基金supported by the National Natural Science Foundation of China(Nos.61271124 and 61471314)the Zhejiang Provincial Natural Science Foundation of China(Nos.LY13F010001 and LY15F010011)
文摘Traditional CMOS technology faces some fundamental physical limitations. Therefore, it has become very important for the integrated circuit industry to continue to develop modem devices and new design methods. The threshold logic gate has attracted much attention because of its powerful logic function. The resonant tunneling diode (RTD) is well suited for imple- menting the threshold logic gate because of its high-speed switching capability, negative differential resistance (NDR) charac- teristic, and functional versatility. In this paper, based on the Reed-Muller (RM) algebraic system, a novel method is proposed to convert three-variable non-threshold functions to the XOR of multiple threshold functions, which is simple and has a program- mable implementation. With this approach, all three-variable non-threshold functions can be presented by the XOR of two threshold functions, except for two special functions. On this basis, a novel three-variable universal logic gate (ULG3) is proposed, composed of two RTD-based universal threshold logic gates (UTLG) and an RTD-based three-variable XOR gate (XOR3). The ULG3 has a simple structure, and a simple method is presented to implement all three-variable functions using one ULG3. Thus, the proposed ULG3 provides a new efficient universal logic gate to implement RTD-based arbitrary n-variable functions.
基金Supported by the National Science Foundation under Grant Nos.90921010,11174373the National Fundamental Research Program of China under Grant No.2010CB923104+2 种基金National Research Foundation and Ministry of Education,Singapore under Grant No.WBS:R-710-000-008-271the 2013 Doctoral Innovation funds of Southwest Jiaotong Universitythe Fundamental Research Funds for the Central Universities
文摘Stark-chirped rapid adiabatic passage(SCRAP) is an important technique used for coherent quantum controls. In this paper we investigate how the practically-existing dissipation of the system influences on the efficiency of the passage, and thus the fidelities of the SCRAP-based quantum gates. With flux-biased Josephson qubits as a specifical example, our results show clearly that the efficiency of the logic gates implemented by SCRAP are robust against the weak dissipation. The influence due to the non-adiabtic transitions between the adiabatic passages is comparatively significantly small. Therefore, the SCRAP-based logic gates should be feasible for the realistic physical systems with noises.
文摘Rural work conference maps out reform plans toimprove China's agriculture industryChina hopes to reform its agriculture sector this year to increase food produce quality,reduce the grain oversupply and help rural populations living in poverty achieve prosperity.The plan was laid out at the end of December of last year when Chinese leaders held a central rural work conference to review how the agriculture industry performed in 2015