Materials Today Quantum最新文献

Thermoelectric quantum oscillations and Zeeman splitting in topological Dirac semimetal BaAl4 拓扑Dirac半金属BaAl4中的热电量子振荡和塞曼分裂

Materials Today Quantum Pub Date : 2025-09-26 DOI: 10.1016/j.mtquan.2025.100054

P.R. Mandal , Kefeng Wang , Tarapada Sarkar , Prathum Saraf , Danila Sokratov , Johnpierre Paglione

{"title":"Thermoelectric quantum oscillations and Zeeman splitting in topological Dirac semimetal BaAl4","authors":"P.R. Mandal , Kefeng Wang , Tarapada Sarkar , Prathum Saraf , Danila Sokratov , Johnpierre Paglione","doi":"10.1016/j.mtquan.2025.100054","DOIUrl":"10.1016/j.mtquan.2025.100054","url":null,"abstract":"<div><div>Three-dimensional topological semimetals hosting Dirac or Weyl fermions are a new kind of materials class in which conduction and valence bands cross each other. Such materials harbor a nontrivial Berry phase, which is an additional geometrical phase factor arising along the path of an adiabatic surface and can give rise to experimentally measurable quantities such as an anomalous Hall component. Here we report a systematic study of quantum oscillations of thermoelectric power in single crystals of the topological Dirac nodal-line semimetal BaAl<sub>4</sub>. We show that the thermoelectric power (TEP) is a sensitive probe of the multiple oscillation frequencies in this material, with two of these frequencies shown to originate from the three-dimensional Dirac band. The detected Berry phase provides evidence of the angular dependence and non-trivial state under high magnetic fields. We also have probed the signatures of Zeeman splitting, from which we have extracted the Landé <span><math><mi>g</mi></math></span>-factor for this system, providing further insight into the non-trivial topology of this family of materials.</div></div>","PeriodicalId":100894,"journal":{"name":"Materials Today Quantum","volume":"8 ","pages":"Article 100054"},"PeriodicalIF":0.0,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145159185","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Projective crystal symmetry and topological phases 投影晶体对称性和拓扑相

Materials Today Quantum Pub Date : 2025-09-25 DOI: 10.1016/j.mtquan.2025.100055

Chen Zhang , Shengyuan A. Yang , Y.X. Zhao

{"title":"Projective crystal symmetry and topological phases","authors":"Chen Zhang , Shengyuan A. Yang , Y.X. Zhao","doi":"10.1016/j.mtquan.2025.100055","DOIUrl":"10.1016/j.mtquan.2025.100055","url":null,"abstract":"<div><div>Quantum states naturally represent symmetry groups, though often in a projective sense. Intriguingly, the projective nature of crystalline symmetries has remained underexplored until very recently. A series of groundbreaking theoretical and experimental studies have now brought this to light, demonstrating that projective representations of crystal symmetries lead to remarkable consequences in condensed matter physics and various artificial crystals, particularly in their connection to topological phenomena. In this article, we explain the basic ideas and notions underpinning these recent developments and share our perspective on this emerging research area. We specifically highlight that the appearance of momentum-space nonsymmorphic symmetry is a unique feature of projective crystal symmetry representations. This, in turn, has the profound consequence of reducing the fundamental domain of momentum space to all possible flat compact manifolds, which include torus and Klein bottle in 2D and the ten platycosms in 3D, presenting a significantly richer landscape for topological structures than conventional settings. Finally, the ongoing efforts and promising future research directions are discussed.</div></div>","PeriodicalId":100894,"journal":{"name":"Materials Today Quantum","volume":"8 ","pages":"Article 100055"},"PeriodicalIF":0.0,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145159187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Nonlinear bulk photocurrent probe Z2 topological phase transition in noncentrosymmetric materials 非中心对称材料中非线性体光电流探针Z2拓扑相变

Materials Today Quantum Pub Date : 2025-09-11 DOI: 10.1016/j.mtquan.2025.100052

Debasis Dutta , Raihan Ahammed , Yingdong Wei , Xiaokai Pan , Xiaoshuang Chen , Lin Wang , Amit Agarwal

{"title":"Nonlinear bulk photocurrent probe Z2 topological phase transition in noncentrosymmetric materials","authors":"Debasis Dutta , Raihan Ahammed , Yingdong Wei , Xiaokai Pan , Xiaoshuang Chen , Lin Wang , Amit Agarwal","doi":"10.1016/j.mtquan.2025.100052","DOIUrl":"10.1016/j.mtquan.2025.100052","url":null,"abstract":"<div><div>Detecting topological phase transitions in bulk is challenging due to the limitations of surface-sensitive probes like ARPES. Here, we demonstrate that nonlinear bulk photocurrents, specifically shift and injection currents, serve as effective probes of <span><math><msub><mrow><mi>Z</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span> topological transitions in noncentrosymmetric materials. These photocurrents show a robust polarity reversal across the <span><math><msub><mrow><mi>Z</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span> phase transition, offering a direct optical signature that distinguishes strong topological phases from weak or trivial ones. This effect originates from a reorganization of key band geometric quantities, the Berry curvature and shift vector, on time-reversal-invariant momentum planes. Using a low-energy Dirac model, we trace this behavior to a band inversion in the time-reversal-invariant momentum plane that drives the topological transition. We validate these findings through tight-binding model for Bi<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>Te<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span> and first-principles calculations for ZrTe<span><math><msub><mrow></mrow><mrow><mn>5</mn></mrow></msub></math></span> and BiTeI, where the topological phase can be tuned by pressure or temperature. Our results establish nonlinear photocurrent as a sensitive and broadly applicable alternative probe of <span><math><msub><mrow><mi>Z</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span> topological phase transitions.</div></div>","PeriodicalId":100894,"journal":{"name":"Materials Today Quantum","volume":"8 ","pages":"Article 100052"},"PeriodicalIF":0.0,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145098463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

RinQ: Towards predicting central sites in proteins on current quantum computers RinQ：在当前的量子计算机上预测蛋白质的中心位置

Materials Today Quantum Pub Date : 2025-09-01 DOI: 10.1016/j.mtquan.2025.100053

Shah Ishmam Mohtashim

引用次数: 0

Improved thermoelectric performance in Cr-doped two-dimensional Bi2Te3 改进了cr掺杂二维Bi2Te3的热电性能

Materials Today Quantum Pub Date : 2025-08-26 DOI: 10.1016/j.mtquan.2025.100051

Jun Beom Park, Rijan Karkee, Michael Thompson Pettes

{"title":"Improved thermoelectric performance in Cr-doped two-dimensional Bi2Te3","authors":"Jun Beom Park, Rijan Karkee, Michael Thompson Pettes","doi":"10.1016/j.mtquan.2025.100051","DOIUrl":"10.1016/j.mtquan.2025.100051","url":null,"abstract":"<div><div>Thermoelectric materials with high electrical conductivity and low thermal conductivity (e.g., Bi<sub>2</sub>Te<sub>3</sub>) can efficiently convert waste heat into electricity. However, despite favorable theoretical predictions, individual Bi<sub>2</sub>Te<sub>3</sub> nanostructures such as two-dimensional (2D) nanoplates tend to underperform bulk Bi<sub>2</sub>Te<sub>3</sub>. We report a novel surface doping technique to synthesize highly n-type Bi<sub>2</sub>Te<sub>3</sub> nanoplates using an external Cr coating followed by a thermal annealing process in a reducing atmosphere, as well as the mechanism by which this surface coating – only a few atoms or less in thickness – can observably impact the thermoelectric performance of 2D Bi<sub>2</sub>Te<sub>3</sub>. The Cr atoms act as n-type carrier donors by directly incorporating into the Bi<sub>2</sub>Te<sub>3</sub> structure during thermal annealing, enhancing electrical conductivity by ∼ 70 % while increasing thermal conductivity by only ∼ 5 % at room temperature. Compared to the uncoated Bi<sub>2</sub>Te<sub>3</sub> nanoplate, the Cr-doped Bi<sub>2</sub>Te<sub>3</sub> nanoplate exhibits a doubled thermoelectric figure of merit (<em>zT</em>), which is still relatively low. Raman spectroscopy and chemical potential simulations further confirm that Cr atoms are incorporated into the Bi<sub>2</sub>Te<sub>3</sub> structure.</div></div>","PeriodicalId":100894,"journal":{"name":"Materials Today Quantum","volume":"7 ","pages":"Article 100051"},"PeriodicalIF":0.0,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144908674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Hexagonal supertetrahedral gallium: a cluster-based three-dimensional topological metal 六方超四面体镓：一种基于团簇的三维拓扑金属

Materials Today Quantum Pub Date : 2025-08-21 DOI: 10.1016/j.mtquan.2025.100050

Yuanze Song , Ting Zhang , Weizhen Meng , Jing Wang , Ying Liu

{"title":"Hexagonal supertetrahedral gallium: a cluster-based three-dimensional topological metal","authors":"Yuanze Song , Ting Zhang , Weizhen Meng , Jing Wang , Ying Liu","doi":"10.1016/j.mtquan.2025.100050","DOIUrl":"10.1016/j.mtquan.2025.100050","url":null,"abstract":"<div><div>Two novel three-dimensional allotropes, designated as hexagonal supertetrahedral aluminum and gallium (<em>h</em>-Al/<em>h</em>-Ga), are proposed based on a hexagonal diamond structure and share the same space group symmetry (<em>P</em>6<sub>3</sub>/<em>mmc</em>) as hexagonal diamond. First-principles calculations demonstrate their structural stability and superior mechanical properties. Notably, these allotropes exhibit distinct electronic characteristics: <em>h</em>-Al behaves as a narrow-bandgap semiconductor, while <em>h</em>-Ga manifests as a topological semimetal with multiple band crossings. We systematically investigate the topological characteristics of <em>h</em>-Ga, which hosts three distinct classes of topological states: triple point, nodal line, and nodal surface, with associated Fermi arcs and drumhead-like surface states. Furthermore, the inclusion of spin-orbit coupling lifts all topological degeneracies, driving a phase transition to a Dirac semimetal. Our findings not only contribute to the expansion of the supertetrahedral materials family but also underscore hexagonal supertetrahedral lattices as a robust and versatile platform for the discovery of diverse topological phases.</div></div>","PeriodicalId":100894,"journal":{"name":"Materials Today Quantum","volume":"7 ","pages":"Article 100050"},"PeriodicalIF":0.0,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144893008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Manifestation of critical effects in environmental parameter estimation using a quantum sensor under dynamical control 动态控制下量子传感器环境参数估计中的临界效应

Materials Today Quantum Pub Date : 2025-08-10 DOI: 10.1016/j.mtquan.2025.100049

M. Cristina Rodríguez , Analia Zwick , Gonzalo A. Álvarez

{"title":"Manifestation of critical effects in environmental parameter estimation using a quantum sensor under dynamical control","authors":"M. Cristina Rodríguez , Analia Zwick , Gonzalo A. Álvarez","doi":"10.1016/j.mtquan.2025.100049","DOIUrl":"10.1016/j.mtquan.2025.100049","url":null,"abstract":"<div><div>Quantum probes offer a powerful platform for exploring environmental dynamics, particularly through their sensitivity to decoherence processes. In this work, we investigate the emergence of critical behavior in the estimation of the environmental memory time <span><math><msub><mrow><mi>τ</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span>, modeled as an Ornstein–Uhlenbeck process characterized by a Lorentzian spectral density. Using dynamically controlled qubit-based sensors—realized experimentally via solid-state Nuclear Magnetic Resonance (NMR) and supported by numerical simulations—we implement tailored filter functions to interrogate the environmental noise spectrum and extract <span><math><msub><mrow><mi>τ</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span> from its spectral width. Our results reveal a sharp transition in estimation performance between short-memory (SM) and long-memory (LM) regimes, reflected in a non-monotonic estimation error that resembles a phase transition. This behavior is accompanied by an avoided-crossing-like structure in the estimated parameter space, indicative of two competing solutions near the critical point. These features underscore the interplay between control, decoherence, and inference in open quantum systems. Beyond their fundamental significance, these critical phenomena offer a practical diagnostic tool for identifying dynamical regimes and optimizing quantum sensing protocols. By exploiting this criticality, our findings pave the way for adaptive control strategies aimed at enhancing precision in quantum parameter estimation—particularly in complex or structured environments such as spin networks, diffusive media, and quantum materials.</div></div>","PeriodicalId":100894,"journal":{"name":"Materials Today Quantum","volume":"7 ","pages":"Article 100049"},"PeriodicalIF":0.0,"publicationDate":"2025-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144831158","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Tailoring electronic, optical, and reactive properties of Br- and F-doped graphene nanoflakes: A DFT-based study Br和f掺杂石墨烯纳米片的电子、光学和反应性质：基于dft的研究

Materials Today Quantum Pub Date : 2025-07-30 DOI: 10.1016/j.mtquan.2025.100048

Mohammed A. Khammat , Alaa M. Khudhair , Noora B. Shwayyea

{"title":"Tailoring electronic, optical, and reactive properties of Br- and F-doped graphene nanoflakes: A DFT-based study","authors":"Mohammed A. Khammat , Alaa M. Khudhair , Noora B. Shwayyea","doi":"10.1016/j.mtquan.2025.100048","DOIUrl":"10.1016/j.mtquan.2025.100048","url":null,"abstract":"<div><div>The present study utilizes density functional theory (DFT) to methodically examine the geometric, electrical, and chemical characteristics of both pure and halogen doped graphene nanoflakes (GNFs). Geometric optimization indicates that the incorporation of bromine and fluorine atoms results in significant lattice distortions, elevated dipole moments, and heightened surface polarity, especially in multi-doped systems. A significant discovery is the adjustable modulation of the electronic band gap: pristine GNFs exhibit a broad band gap of 4.172 eV, whereas halogen doping substantially reduces this value resulting in 1.548 eV for BrF-GNFs, 1.580 eV for 2Br-GNFs, 1.676 eV for 2F-GNFs, 1.426 eV for Br<sub>2</sub>F<sub>2</sub>-GNFs, and as low as 1.194 eV for Br<sub>3</sub>F<sub>3</sub>-GNFs. This decrease is ascribed to the concentration of frontier molecular orbitals at dopant locations and the formation of mid-gap electronic states. Doping induces substantial alterations in the Fermi level and considerable enhancements in work function, reaching values as high as 4.364 eV in Br<sub>2</sub>F<sub>2</sub>-GNFs, which is beneficial for device applications. Chemical reactivity indices demonstrate that doped GNFs possess enhanced electrophilicity, softness, and a heightened tendency for electron transfer relative to virgin GNFs. These findings together indicate that halogen doping is a viable method for modifying the band gap and chemical reactivity of graphene nanoflakes, hence expanding their use in nanoelectronics, optoelectronics catalysis, and sensing technologies.</div></div>","PeriodicalId":100894,"journal":{"name":"Materials Today Quantum","volume":"7 ","pages":"Article 100048"},"PeriodicalIF":0.0,"publicationDate":"2025-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144770777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Optimizing lossy state preparation for quantum sensing using Hamiltonian engineering 利用哈密顿工程优化量子传感的有损态制备

Materials Today Quantum Pub Date : 2025-07-26 DOI: 10.1016/j.mtquan.2025.100046

Bharath Hebbe Madhusudhana

{"title":"Optimizing lossy state preparation for quantum sensing using Hamiltonian engineering","authors":"Bharath Hebbe Madhusudhana","doi":"10.1016/j.mtquan.2025.100046","DOIUrl":"10.1016/j.mtquan.2025.100046","url":null,"abstract":"<div><div>One of the most prominent platforms for demonstrating quantum sensing below the standard quantum limit is the spinor Bose–Einstein condensate. While a quantum advantage using several tens of thousands of atoms has been demonstrated in this platform, it faces an important challenge: atom loss. Atom loss is a Markovian error process modeled by Lindblad jump operators, and a no-go theorem, which we also show here, states that the loss of atoms in all spin components reduces the quantum advantage to a constant factor. Here, we show that this no-go theorem can be circumvented if we constrain atom losses to a <em>single</em> spin component. Moreover, we show that in this case, the maximum quantum Fisher information with <span><math><mi>N</mi></math></span> atoms scales as <span><math><msup><mrow><mi>N</mi></mrow><mrow><mn>3</mn><mo>/</mo><mn>2</mn></mrow></msup></math></span>, establishing that a <em>scalable</em> quantum advantage can be achieved <em>despite</em> atom loss. Although Lindblad jump operators are generally non-Hermitian and non-invertible, we use their <em>Moore–Penrose inverse</em> to develop a framework for constructing several states with this scaling of Fisher information in the presence of losses. We use Hamiltonian engineering with realistic Hamiltonians to develop experimental protocols for preparing these states. Finally, we discuss possible experimental techniques to constrain the losses to a single spin mode.</div></div>","PeriodicalId":100894,"journal":{"name":"Materials Today Quantum","volume":"7 ","pages":"Article 100046"},"PeriodicalIF":0.0,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144757093","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Investigation of structural and external parameters affecting the efficiency of quantum dot solar cells: A modified detailed-balance model study 影响量子点太阳能电池效率的结构和外部参数研究：一种改进的详细平衡模型研究

Materials Today Quantum Pub Date : 2025-07-22 DOI: 10.1016/j.mtquan.2025.100047

Fatih Koc , Carlos A. Duque , Mehmet Sahin

{"title":"Investigation of structural and external parameters affecting the efficiency of quantum dot solar cells: A modified detailed-balance model study","authors":"Fatih Koc , Carlos A. Duque , Mehmet Sahin","doi":"10.1016/j.mtquan.2025.100047","DOIUrl":"10.1016/j.mtquan.2025.100047","url":null,"abstract":"<div><div>In this study, the power conversion efficiency (PCE) of InP/GaAs/GaSb quantum dot solar cell (QDSC) with type II confinement regime is investigated depending on different structural parameters such as, core radius, spacer layer, and outer shell thickness using both original detailed balance model (ODBM) developed by Shockley and Queisser, and modified detailed balance model (MDBM). Moreover, the effect of external parameters such as temperature and hydrostatic pressure on the PCE is also investigated, and the possible physical reasons are discussed in detail and comparatively. The results show that the MDBM can better reveal the critical effects of the structural parameters, i.e., the size and material properties and the confinement regime on the PCE. A significant result related to this shows that the PCE of the InP/GaAs/GaSb QDSC model can be optimized by adjusting the spacer material thickness to maintain the effective energy gap at different fixed values. At the same time, it is seen that the MDBM is also more successful in determining the effects of external parameters on the PCE. This study develops a novel method of determining the best device parameters by thoroughly investigating the impact of structural and external parameters on the PCE of QDSCs.</div></div>","PeriodicalId":100894,"journal":{"name":"Materials Today Quantum","volume":"7 ","pages":"Article 100047"},"PeriodicalIF":0.0,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144713469","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0