In discrete-variable quantum computation,non-Clifford T-gates play a pivotal role in achieving genuine quantum advantage.However,in the literature,T-gates are only defined for prime dimensional systems,and the absence...In discrete-variable quantum computation,non-Clifford T-gates play a pivotal role in achieving genuine quantum advantage.However,in the literature,T-gates are only defined for prime dimensional systems,and the absence of their high-dimensional counterparts in non-prime dimensional systems raises the issue of how to introduce certain T-gates in such systems.In continuous-variable quantum computation,universality is achieved through a combination of Gaussian gates and some non-Gaussian gates,such as the widely used cubic phase gates.In this work,we establish some connections between discrete-variable(Clifford/non-Clifford)gates and continuous-variable(Gaussian/non-Gaussian)gates via the powerful GKP(Gottesman-Kitaev-Preskill)encoding,which maps qudits to oscillators and serves as a bridge between discrete and continuous realms.By exploiting the analogies between the Clifford hierarchy and the Gaussian hierarchy,we derive(discrete-variable)T-gates in arbitrary(not necessarily prime)dimensional systems from well established(continuous-variable)cubic phase gates.We reveal some basic properties of the unified T-gates,and make a comparative study of various T-gates.As an application,we employ the T-gates to construct equidistributed n-angular frames and certain MUBs(mutually unbiased bases).展开更多
We propose and fabricate an A1GaN/GaN high electron mobility transistor （HEMT） on sapphire substrate using a new kind of electron beam （EB） lithography layout for the T-gate. Using this new layout,we can change th...We propose and fabricate an A1GaN/GaN high electron mobility transistor （HEMT） on sapphire substrate using a new kind of electron beam （EB） lithography layout for the T-gate. Using this new layout,we can change the aspect ratio （ratio of top gate dimension to gate length） and modify the shape of the T-gate freely. Therefore, we obtain a 0.18μm gate-length AlGaN/GaN HEMT with a unity current gain cutoff frequency （fT） of 65GHz. The aspect ratio of the T-gate is 10. These single finger devices also exhibit a peak extrinsic transconductance of 287mS/mm and a maximum drain current as high as 980mA/mm.展开更多
In the stabilizer formalism of fault-tolerant quantum computation,stabilizer states serve as classical objects,while magic states(non-stabilizer states)are a kind of quantum resource(called magic resource)for promotin...In the stabilizer formalism of fault-tolerant quantum computation,stabilizer states serve as classical objects,while magic states(non-stabilizer states)are a kind of quantum resource(called magic resource)for promoting stabilizer circuits to universal quantum computation.In this framework,the T-gate is widely used as a non-Clifford gate which generates magic resource from stabilizer states.A natural question arises as whether the T-gate is in some sense optimal for generating magic resource.We address this issue by employing an intuitive and computable quantifier of magic based on characteristic functions(Weyl transforms)of quantum states.We demonstrate that the qubit T-gate,as well as its qutrit extension,the qutrit T-gate,are indeed optimal for generating magic resource among the class of diagonal unitary operators.Moreover,up to Clifford equivalence,the T-gate is essentially the only gate having such an optimal property.This reveals some intrinsic optimal features of the T-gate.We further compare the T-gate with general unitary gates for generating magic resource.展开更多
We connect magic(non-stabilizer)states,symmetric informationally complete positive operator valued measures(SIC-POVMs),and mutually unbiased bases(MUBs)in the context of group frames,and study their interplay.Magic st...We connect magic(non-stabilizer)states,symmetric informationally complete positive operator valued measures(SIC-POVMs),and mutually unbiased bases(MUBs)in the context of group frames,and study their interplay.Magic states are quantum resources in the stabilizer formalism of quantum computation.SIC-POVMs and MUBs are fundamental structures in quantum information theory with many applications in quantum foundations,quantum state tomography,and quantum cryptography,etc.In this work,we study group frames constructed from some prominent magic states,and further investigate their applications.Our method exploits the orbit of discrete Heisenberg-Weyl group acting on an initial fiducial state.We quantify the distance of the group frames from SIC-POVMs and MUBs,respectively.As a simple corollary,we reproduce a complete family of MUBs of any prime dimensional system by introducing the concept of MUB fiducial states,analogous to the well-known SIC-POVM fiducial states.We present an intuitive and direct construction of MUB fiducial states via quantum T-gates,and demonstrate that for the qubit system,there are twelve MUB fiducial states,which coincide with the H-type magic states.We compare MUB fiducial states and SIC-POVM fiducial states from the perspective of magic resource for stabilizer quantum computation.We further pose the challenging issue of identifying all MUB fiducial states in general dimensions.展开更多
This paper applies a novel quad-layer resist and e-beam lithography technique to fabricate a GaAs-based InAlAs/InGaAs metamorphic high electron mobility transistor （HEMT） grown by metal organic chemical vapour depos...This paper applies a novel quad-layer resist and e-beam lithography technique to fabricate a GaAs-based InAlAs/InGaAs metamorphic high electron mobility transistor （HEMT） grown by metal organic chemical vapour deposition （MOCVD）. The gate length of the metamorphic HEMT was 150 nm, the maximum current density was 330 mA/mm, the maximum transconductanee was 470 mS/mm, the threshold voltage was -0.6 V, and the maximum current gain cut-off frequency and maximum oscillation frequency were 102 GHz and 450 GHz, respectively. This is the first report on tri-termination devices whose frequency value is above 400 GHz in China. The excellent frequency performances promise the possibility of metamorphic HEMTs grown by MOCVD for millimetre-wave applications, and more outstanding device performances would be obtained after optimizing the material structure, the elaborate T-gate and other device processes further.展开更多
A self-supporting T-shaped gate(SST-gate) GaN device and process method using electron beam lithography are proposed.An AlGaN/GaN high-electron-mobility transistor(HEMT) device with a gate length of 100 nm is fabricat...A self-supporting T-shaped gate(SST-gate) GaN device and process method using electron beam lithography are proposed.An AlGaN/GaN high-electron-mobility transistor(HEMT) device with a gate length of 100 nm is fabricated by this method.The current gain cutoff frequency(f_(T)) is 60 GHz,and the maximum oscillation frequency(f_(max)) is 104 GHz.The current collapse has improved by 13% at static bias of(V_(GSQ),V_(DSQ))=(-8 V,10 V),and gate manufacturing yield has improved by 17% compared with the traditional floating T-shaped gate(FT-gate) device.展开更多
It is obviously advantageous to use single-pattern cell ternary tree (T-gate)network to obtain ternary logic function. Many scholars at home and abroad have done much in minimization of T-gate realization of multiple-...It is obviously advantageous to use single-pattern cell ternary tree (T-gate)network to obtain ternary logic function. Many scholars at home and abroad have done much in minimization of T-gate realization of multiple-valued logic. It is generally acknowledged that it is necessary to try N! times in order to get an optimal result. However, using the Input Vector Map presented here, which is as simple and convenient as Binary Karnaugh Map, we can get an optimal result by trying only N times.展开更多
High performance 150-nm gate-length metamorphic Al0.48In0.52As/Ga0.47In0.53 As high electron mobility transistors(mHEMTs) with very good device performance have been successfully fabricated.A T-shaped gate is fabricat...High performance 150-nm gate-length metamorphic Al0.48In0.52As/Ga0.47In0.53 As high electron mobility transistors(mHEMTs) with very good device performance have been successfully fabricated.A T-shaped gate is fabricated by using a combined technique of optical and e-beam photolithography,which is beneficial to decreasing parasitic capacitance and parasitic resistance of the gate.The ohmic contact resistance R c is as low as 0.03 mm when using a novel ohmic contact metal system(Ni/Ge/Ti/Au).The devices exhibit excellent DC and RF performance.A peak extrinsic transconductance of 775 mS/mm and a maximum drain current density of 720 mA/mm are achieved.The unity current gain cut-off frequency(fT) and the maximum oscillation frequency(f max) are 188.4 and 250 GHz,respectively.展开更多
AlGaN/GaN high electron mobility transistors（HEMTs）with high performance were fabricated and characterized.A variety of techniques were used to improve device performance,such as AlN interlayer,silicon nitride passi...AlGaN/GaN high electron mobility transistors（HEMTs）with high performance were fabricated and characterized.A variety of techniques were used to improve device performance,such as AlN interlayer,silicon nitride passivation,high aspect ratio T-shaped gate,low resistance ohmic contact and short drain-source distance. DC and RF performances of as-fabricated HEMTs were characterized by utilizing a semiconductor characterization system and a vector network analyzer,respectively.As-fabricated devices exhibited a maximum drain current density of 1.41 A/mm and a maximum peak extrinsic transconductance of 317 mS/mm.The obtained current density is larger than those reported in the literature to date,implemented with a domestic wafer and processes.Furthermore, a unity current gain cut-off frequency of 74.3 GHz and a maximum oscillation frequency of 112.4 GHz were obtained on a device with an 80 nm gate length.展开更多
基金supported the National Natural Science Foundation of China,Grant Nos.12341103 and 12426671by the National Key R&D Program of China,Grant No.2020YFA0712700.
文摘In discrete-variable quantum computation,non-Clifford T-gates play a pivotal role in achieving genuine quantum advantage.However,in the literature,T-gates are only defined for prime dimensional systems,and the absence of their high-dimensional counterparts in non-prime dimensional systems raises the issue of how to introduce certain T-gates in such systems.In continuous-variable quantum computation,universality is achieved through a combination of Gaussian gates and some non-Gaussian gates,such as the widely used cubic phase gates.In this work,we establish some connections between discrete-variable(Clifford/non-Clifford)gates and continuous-variable(Gaussian/non-Gaussian)gates via the powerful GKP(Gottesman-Kitaev-Preskill)encoding,which maps qudits to oscillators and serves as a bridge between discrete and continuous realms.By exploiting the analogies between the Clifford hierarchy and the Gaussian hierarchy,we derive(discrete-variable)T-gates in arbitrary(not necessarily prime)dimensional systems from well established(continuous-variable)cubic phase gates.We reveal some basic properties of the unified T-gates,and make a comparative study of various T-gates.As an application,we employ the T-gates to construct equidistributed n-angular frames and certain MUBs(mutually unbiased bases).
文摘We propose and fabricate an A1GaN/GaN high electron mobility transistor （HEMT） on sapphire substrate using a new kind of electron beam （EB） lithography layout for the T-gate. Using this new layout,we can change the aspect ratio （ratio of top gate dimension to gate length） and modify the shape of the T-gate freely. Therefore, we obtain a 0.18μm gate-length AlGaN/GaN HEMT with a unity current gain cutoff frequency （fT） of 65GHz. The aspect ratio of the T-gate is 10. These single finger devices also exhibit a peak extrinsic transconductance of 287mS/mm and a maximum drain current as high as 980mA/mm.
基金supported by the National Key R&D Program of China,Grant No.2020YFA0712700the National Natural Science Foundation of China,Grant No.11875317。
文摘In the stabilizer formalism of fault-tolerant quantum computation,stabilizer states serve as classical objects,while magic states(non-stabilizer states)are a kind of quantum resource(called magic resource)for promoting stabilizer circuits to universal quantum computation.In this framework,the T-gate is widely used as a non-Clifford gate which generates magic resource from stabilizer states.A natural question arises as whether the T-gate is in some sense optimal for generating magic resource.We address this issue by employing an intuitive and computable quantifier of magic based on characteristic functions(Weyl transforms)of quantum states.We demonstrate that the qubit T-gate,as well as its qutrit extension,the qutrit T-gate,are indeed optimal for generating magic resource among the class of diagonal unitary operators.Moreover,up to Clifford equivalence,the T-gate is essentially the only gate having such an optimal property.This reveals some intrinsic optimal features of the T-gate.We further compare the T-gate with general unitary gates for generating magic resource.
基金supported by the National Key R&D Program of China,Grant No.2020YFA0712700the National Natural Science Foundation of China‘Mathematical Basic Theory of Quantum Computing’special project,Grant No.12341103。
文摘We connect magic(non-stabilizer)states,symmetric informationally complete positive operator valued measures(SIC-POVMs),and mutually unbiased bases(MUBs)in the context of group frames,and study their interplay.Magic states are quantum resources in the stabilizer formalism of quantum computation.SIC-POVMs and MUBs are fundamental structures in quantum information theory with many applications in quantum foundations,quantum state tomography,and quantum cryptography,etc.In this work,we study group frames constructed from some prominent magic states,and further investigate their applications.Our method exploits the orbit of discrete Heisenberg-Weyl group acting on an initial fiducial state.We quantify the distance of the group frames from SIC-POVMs and MUBs,respectively.As a simple corollary,we reproduce a complete family of MUBs of any prime dimensional system by introducing the concept of MUB fiducial states,analogous to the well-known SIC-POVM fiducial states.We present an intuitive and direct construction of MUB fiducial states via quantum T-gates,and demonstrate that for the qubit system,there are twelve MUB fiducial states,which coincide with the H-type magic states.We compare MUB fiducial states and SIC-POVM fiducial states from the perspective of magic resource for stabilizer quantum computation.We further pose the challenging issue of identifying all MUB fiducial states in general dimensions.
基金Project supported by the State Key Development Program for Basic Research of China (Grant No. G2002CB311901)Institute of Microelectronics,Chinese Academy of Sciences,Dean Fund (Grant No. 06SB124004)
文摘This paper applies a novel quad-layer resist and e-beam lithography technique to fabricate a GaAs-based InAlAs/InGaAs metamorphic high electron mobility transistor （HEMT） grown by metal organic chemical vapour deposition （MOCVD）. The gate length of the metamorphic HEMT was 150 nm, the maximum current density was 330 mA/mm, the maximum transconductanee was 470 mS/mm, the threshold voltage was -0.6 V, and the maximum current gain cut-off frequency and maximum oscillation frequency were 102 GHz and 450 GHz, respectively. This is the first report on tri-termination devices whose frequency value is above 400 GHz in China. The excellent frequency performances promise the possibility of metamorphic HEMTs grown by MOCVD for millimetre-wave applications, and more outstanding device performances would be obtained after optimizing the material structure, the elaborate T-gate and other device processes further.
基金Project supported by the National Natural Science Foundation of China(Grant No.62188102)the Natural Science Basic Research Program of Shaanxi Province,China(Grant No.2022JM-316)the Fund from the Ministry of Education of China(Grant No.8091B042112)。
文摘A self-supporting T-shaped gate(SST-gate) GaN device and process method using electron beam lithography are proposed.An AlGaN/GaN high-electron-mobility transistor(HEMT) device with a gate length of 100 nm is fabricated by this method.The current gain cutoff frequency(f_(T)) is 60 GHz,and the maximum oscillation frequency(f_(max)) is 104 GHz.The current collapse has improved by 13% at static bias of(V_(GSQ),V_(DSQ))=(-8 V,10 V),and gate manufacturing yield has improved by 17% compared with the traditional floating T-shaped gate(FT-gate) device.
文摘It is obviously advantageous to use single-pattern cell ternary tree (T-gate)network to obtain ternary logic function. Many scholars at home and abroad have done much in minimization of T-gate realization of multiple-valued logic. It is generally acknowledged that it is necessary to try N! times in order to get an optimal result. However, using the Input Vector Map presented here, which is as simple and convenient as Binary Karnaugh Map, we can get an optimal result by trying only N times.
基金supported by the National Natural Science Foundation of China(Grant Nos.61274026,60274077 and 60976068)the Scientific Research Fund of Hunan Provincial Education Department(Grant No. 10C0709)the Science and Technology Plan Foundation of Hunan Province(Grant No.2011GK3058)
文摘High performance 150-nm gate-length metamorphic Al0.48In0.52As/Ga0.47In0.53 As high electron mobility transistors(mHEMTs) with very good device performance have been successfully fabricated.A T-shaped gate is fabricated by using a combined technique of optical and e-beam photolithography,which is beneficial to decreasing parasitic capacitance and parasitic resistance of the gate.The ohmic contact resistance R c is as low as 0.03 mm when using a novel ohmic contact metal system(Ni/Ge/Ti/Au).The devices exhibit excellent DC and RF performance.A peak extrinsic transconductance of 775 mS/mm and a maximum drain current density of 720 mA/mm are achieved.The unity current gain cut-off frequency(fT) and the maximum oscillation frequency(f max) are 188.4 and 250 GHz,respectively.
文摘AlGaN/GaN high electron mobility transistors（HEMTs）with high performance were fabricated and characterized.A variety of techniques were used to improve device performance,such as AlN interlayer,silicon nitride passivation,high aspect ratio T-shaped gate,low resistance ohmic contact and short drain-source distance. DC and RF performances of as-fabricated HEMTs were characterized by utilizing a semiconductor characterization system and a vector network analyzer,respectively.As-fabricated devices exhibited a maximum drain current density of 1.41 A/mm and a maximum peak extrinsic transconductance of 317 mS/mm.The obtained current density is larger than those reported in the literature to date,implemented with a domestic wafer and processes.Furthermore, a unity current gain cut-off frequency of 74.3 GHz and a maximum oscillation frequency of 112.4 GHz were obtained on a device with an 80 nm gate length.
