Kexin Zhang, Hugo V. Lepage, Ying Dong, Crispin H. W. Barnes
{"title":"Charge qubits based on ultra-thin topological insulator films","authors":"Kexin Zhang, Hugo V. Lepage, Ying Dong, Crispin H. W. Barnes","doi":"10.1007/s11467-023-1364-5","DOIUrl":"10.1007/s11467-023-1364-5","url":null,"abstract":"<div><p>We study how to use the surface states in a Bi<sub>2</sub>Se<sub>3</sub> topological insulator ultra-thin film that are affected by finite size effects for the purpose of quantum computing. We demonstrate that: (i) surface states under the finite size effect can effectively form a two-level system where their energy levels lie in between the bulk energy gap and a logic qubit can be constructed, (ii) the qubit can be initialized and manipulated using electric pulses of simple forms, (iii) two-qubit entanglement is achieved through a <span>(sqrt {{rm{SWAP}}} )</span> operation when the two qubits are in a parallel setup, and (iv) alternatively, a Floquet state can be exploited to construct a qubit and two Floquet qubits can be entangled through a Controlled-NOT operation. The Floquet qubit offers robustness to background noise since there is always an oscillating electric field applied, and the single qubit operations are controlled by amplitude modulation of the oscillating field, which is convenient experimentally.\u0000</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":573,"journal":{"name":"Frontiers of Physics","volume":"19 3","pages":""},"PeriodicalIF":7.5,"publicationDate":"2023-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139054436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xiangkun Zeng, Chenyu Wan, Zhichen Zhao, Di Huang, Zhanshan Wang, Xinbin Cheng, Tao Jiang
{"title":"Nonlinear optics of two-dimensional heterostructures","authors":"Xiangkun Zeng, Chenyu Wan, Zhichen Zhao, Di Huang, Zhanshan Wang, Xinbin Cheng, Tao Jiang","doi":"10.1007/s11467-023-1363-6","DOIUrl":"10.1007/s11467-023-1363-6","url":null,"abstract":"<div><p>Two-dimensional (2D) materials exhibit exceptionally strong nonlinear optical responses, benefiting from their reduced dimensionality, relaxed phase-matching requirements, and enhanced light-matter interaction. With additional degrees of freedom in the modulation of the physical properties by stacking 2D layers together, nonlinear optics of 2D heterostructures becomes increasingly fascinating. In this perspective, we provide a brief overview of recent advances in the field of nonlinear optics of 2D heterostructures, with a particular focus on their remarkable capabilities in characterization and modulation. Given the recent advances and the emergence of novel heterostructures, combined with innovative tuning knobs and advanced nonlinear optical techniques, we anticipate deeper insights into the underlying mechanisms and more associated applications in this rapidly evolving field.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":573,"journal":{"name":"Frontiers of Physics","volume":"19 3","pages":""},"PeriodicalIF":7.5,"publicationDate":"2023-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138745545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Efficiently simulating the work distribution of multiple identical bosons with boson sampling","authors":"Wen-Qiang Liu, Zhang-qi Yin","doi":"10.1007/s11467-023-1366-3","DOIUrl":"10.1007/s11467-023-1366-3","url":null,"abstract":"<div><p>Boson sampling has been theoretically proposed and experimentally demonstrated to show quantum computational advantages. However, it still lacks the deep understanding of the practical applications of boson sampling. Here we propose that boson sampling can be used to efficiently simulate the work distribution of multiple identical bosons. We link the work distribution to boson sampling and numerically calculate the transition amplitude matrix between the single-boson eigenstates in a one-dimensional quantum piston system, and then map the matrix to a linear optical network of boson sampling. The work distribution can be efficiently simulated by the output probabilities of boson sampling using the method of the grouped probability estimation. The scheme requires at most a polynomial number of the samples and the optical elements. Our work opens up a new path towards the calculation of complex quantum work distribution using only photons and linear optics.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":573,"journal":{"name":"Frontiers of Physics","volume":"19 3","pages":""},"PeriodicalIF":7.5,"publicationDate":"2023-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138745597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Transmission-reflection decoupling of non-Hermitian photonic doping epsilon-near-zero media","authors":"Yongxing Wang \u0000 (, ), Jizi Lin \u0000 (, ), Ping Xu \u0000 (, )","doi":"10.1007/s11467-023-1362-7","DOIUrl":"10.1007/s11467-023-1362-7","url":null,"abstract":"<div><p>We present a novel method to achieve the decoupling between the transmission and reflection waves of non-Hermitian doped epsilon-near-zero (ENZ) media by inserting a dielectric slit into the structure. Our method also allows for independent control over the amplitude and the phase of both the transmission and reflection waves through few dopants, enabling us to achieve various optical effects, such as perfect absorption, high-gain reflection without transmission, reflectionless high-gain transmission and reflectionless total transmission with different phases. By manipulating the permittivity of dopants with extremely low loss or gain, we can realize these effects in the same configuration. We also extend this principle to multi-port doped ENZ structures and design a highly reconfigurable and reflectionless signal distributor and generator that can split, amplify, decay and phase-shift the input signal in any desired way. Our method overcomes limitations of optical manipulation in doped ENZ caused by the interdependent nature of the transmission and reflection, and has potential applications in novel photonic devices.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":573,"journal":{"name":"Frontiers of Physics","volume":"19 3","pages":""},"PeriodicalIF":7.5,"publicationDate":"2023-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138745812","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chengxiang Jiao, Kai Huang, Hongli Guo, Xingxia Cui, Qing Yuan, Cancan Lou, Guangqiang Mei, Chunlong Wu, Nan Xu, Limin Cao, Min Feng
{"title":"Resonant four-photon photoemission from SnSe2(001)","authors":"Chengxiang Jiao, Kai Huang, Hongli Guo, Xingxia Cui, Qing Yuan, Cancan Lou, Guangqiang Mei, Chunlong Wu, Nan Xu, Limin Cao, Min Feng","doi":"10.1007/s11467-023-1365-4","DOIUrl":"10.1007/s11467-023-1365-4","url":null,"abstract":"<div><p>High-order nonlinear multiphoton absorption is usually inefficient, but can be enhanced by designing resonant excitations between occupied and unoccupied energy levels. We conducted angle-resolved multi-photon photoemission (mPPE) studies on the SnSe<sub>2</sub>(001) surfaces excited by ultrashort laser pulses. By tuning photon energy and light polarization, we demonstrate the presence of a resonant four-photon photoemission (4PPE) process involving the occupied valence band (VB), the unoccupied second conduction band (CB2) and the unoccupied image-potential state (IPs) of SnSe<sub>2</sub>. In this 4PPE process, VB electrons of SnSe<sub>2</sub> are resonantly excited into CB2 by adsorbing two photons, followed by the adsorption of another photon to populate the <i>n</i> = 1 IPs before being emitted out to the vacuum by adsorbing one more photon. This results in a double-resonant 4PPE process, which exhibits approximately a 40 times enhancement in photoemission yields compared to cases where one of the resonant pathways, CB2 → IPs, is inhibited by involving a virtual state instead of the IPs in the 4PPE. The double-resonant 4PPE process efficiently excite the bulk VB electrons outside the vacuum, like taking advantage of resonant “ladders” through two real empty electronic states of SnSe<sub>2</sub>. Our results highlight the important applications of mPPE in probing the band-structure, particularly the unoccupied states, of recently emerging main group dichalcogenide semiconductors. Furthermore, the discovered resonant mPPE process contributes to the exploration of their promising optoelectronic applications.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":573,"journal":{"name":"Frontiers of Physics","volume":"19 3","pages":""},"PeriodicalIF":7.5,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138713678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Localization of q-form fields on a de Sitter brane in chameleon gravity","authors":"Yi Zhong, Tao-Tao Sui","doi":"10.1007/s11467-023-1361-8","DOIUrl":"10.1007/s11467-023-1361-8","url":null,"abstract":"<div><p>Recently, it was found that the vector field can be naturally localized on the thick brane in chameleon gravity. In this work, we extend this study to encompass de Sitter brane scenario. We focus on the localization of <i>q</i>-form fields. The scalar and vector fields can be localized on the de Sitter brane, while the KR field cannot be localized. The condition for localization of the scalar and vector fields is obtained. Furthermore, we investigate the localization characteristics in two examples with given conformal factor <i>b</i>(<i>φ</i>). In the first case, the effective potentials and KK modes of the matter fields are obtained asymmetric even though the de Sitter brane has <i>Z</i><sub>2</sub> symmetry. In the second case, volcano-like effective potentials are generated in the de Sitter brane model.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":573,"journal":{"name":"Frontiers of Physics","volume":"19 3","pages":""},"PeriodicalIF":7.5,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138713692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chui-Ping Yang, Jia-Heng Ni, Liang Bin, Yu Zhang, Yang Yu, Qi-Ping Su
{"title":"Preparation of maximally-entangled states with multiple cat-state qutrits in circuit QED","authors":"Chui-Ping Yang, Jia-Heng Ni, Liang Bin, Yu Zhang, Yang Yu, Qi-Ping Su","doi":"10.1007/s11467-023-1357-4","DOIUrl":"10.1007/s11467-023-1357-4","url":null,"abstract":"<div><p>In recent years, cat-state encoding and high-dimensional entanglement have attracted much attention. However, previous works are limited to generation of entangled states of cat-state qubits (two-dimensional entanglement with cat-state encoding), while how to prepare entangled states of cat-state qutrits or qudits (high-dimensional entanglement with cat-state encoding) has not been investigated. We here propose to generate a maximally-entangled state of multiple cat-state qutrits (three-dimensional entanglement by cat-state encoding) in circuit QED. The entangled state is prepared with multiple microwave cavities coupled to a superconducting flux ququart (a four-level quantum system). This proposal operates essentially by the cavity-qutrit dispersive interaction. The circuit hardware resource is minimized because only a coupler ququart is employed. The higher intermediate level of the ququart is occupied only for a short time, thereby decoherence from this level is greatly suppressed during the state preparation. Remarkably, the state preparation time does not depend on the number of the qutrits, thus it does not increase with the number of the qutrits. As an example, our numerical simulations demonstrate that, with the present circuit QED technology, the high-fidelity preparation is feasible for a maximally-entangled state of two cat-state qutrits. Furthermore, we numerically analyze the effect of the inter-cavity crosstalk on the scalability of this proposal. This proposal is universal and can be extended to accomplish the same task with multiple microwave or optical cavities coupled to a natural or artificial four-level atom.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":573,"journal":{"name":"Frontiers of Physics","volume":"19 3","pages":""},"PeriodicalIF":7.5,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138713676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ernest Grodner, Michał Kowalczyk, Julian Srebrny, Leszek Próchniak, Chrystian Droste, Jan Kownacki, Maciej Kisieliński, Krzysztof Starosta, Takeshi Koike
{"title":"The g-factor measurement as an ultimate test for nuclear chirality","authors":"Ernest Grodner, Michał Kowalczyk, Julian Srebrny, Leszek Próchniak, Chrystian Droste, Jan Kownacki, Maciej Kisieliński, Krzysztof Starosta, Takeshi Koike","doi":"10.1007/s11467-023-1359-2","DOIUrl":"10.1007/s11467-023-1359-2","url":null,"abstract":"<div><p>We present results of a series of experiments aimed at finding the most direct fingerprints of a phenomenon of nuclear chirality. These experiments brought a detailed knowledge of the so called partner bands in <sup>132</sup>La, <sup>128</sup>Cs and <sup>126</sup>Cs including absolute values of E2 and Ml transition probabilities obtained through the DSA (Doppler Shift Attenuation) method. Considering the indirect character of observables such as energies and transition rates we proposed measurement of the <i>g</i>-factor of a chosen state as a direct, ultimate test of chirality. Our experiment on the bandhead of partner bands in <sup>128</sup>Cs showed feasibility of this approach. Measured value of the <i>g</i>-factor which suggests non-chiral character of this state leads to another puzzle in the chirality studies — how the chirality emerges with increasing spin of levels along a partner band.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":573,"journal":{"name":"Frontiers of Physics","volume":"19 3","pages":""},"PeriodicalIF":7.5,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138713677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Curved anisotropic polaritons","authors":"Tao Hou, Yixiao Ge, Shuwen Xue, Huanyang Chen","doi":"10.1007/s11467-023-1360-9","DOIUrl":"10.1007/s11467-023-1360-9","url":null,"abstract":"<div><p>The curved surface has emerged as new research platform for understanding and manipulating novel electromagnetic behaviors in complex media. In this paper, we explore the anisotropic polaritons on the spherical surface based on Maxwell’s fish-eye metric through stereographic projection. Additionally, this phenomenon can be extended to spindle surface by conformal mapping. Our calculations and simulations demonstrate the elliptic and hyperbolic polaritons, excited by an electric dipole on the sphere, will self-focus or focus on the poles on the sphere affected by anisotropic permittivity. Furthermore, we reveal the optical singularity nature of the curved hyperbolic polaritons from the perspective of transformation optics by obtaining the equivalent optical refractive index profiles and the particle potential energy. Based on natural anisotropic materials and metamaterials, the curved polaritons have potential applications in curved surface focusing and chaos regulation. This work not only bridges the transformation optics and anisotropic polaritons at curved surface, but also provides a new route to surface optical field manipulation.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":573,"journal":{"name":"Frontiers of Physics","volume":"19 3","pages":""},"PeriodicalIF":7.5,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138713688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Classification of spin Hall effect in two-dimensional systems","authors":"Longjun Xiang, Fuming Xu, Luyang Wang, Jian Wang","doi":"10.1007/s11467-023-1358-3","DOIUrl":"10.1007/s11467-023-1358-3","url":null,"abstract":"<div><p>Physical properties such as the conductivity are usually classified according to the symmetry of the underlying system using Neumann’s principle, which gives an upper bound for the number of independent components of the corresponding property tensor. However, for a given Hamiltonian, this global approach usually can not give a definite answer on whether a physical effect such as spin Hall effect (SHE) exists or not. It is found that the parity and types of spin-orbit interactions (SOIs) are good indicators that can further reduce the number of independent components of the spin Hall conductivity for a specific system. In terms of the parity as well as various Rashba-like and Dresselhaus-like SOIs, we propose a local approach to classify SHE in two-dimensional (2D) two-band models, where sufficient conditions for identifying the existence or absence of SHE in all 2D magnetic point groups are presented.\u0000</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":573,"journal":{"name":"Frontiers of Physics","volume":"19 3","pages":""},"PeriodicalIF":7.5,"publicationDate":"2023-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135086666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}