物理最新文献

{"title":"Tripartite measurement uncertainty in Schwarzschild space-time","authors":"Hazhir Dolatkhah,&nbsp;Artur Czerwinski,&nbsp;Asad Ali,&nbsp;Saif Al-Kuwari,&nbsp;Saeed Haddadi","doi":"10.1140/epjc/s10052-024-13554-3","DOIUrl":"10.1140/epjc/s10052-024-13554-3","url":null,"abstract":"<div><p>The effect of Hawking radiation on tripartite measurement uncertainty in a Schwarzschild black hole background is analyzed in this study. Two scenarios are examined. In the first, quantum memory particles approach a Schwarzschild black hole and are positioned near the event horizon, while the particle being measured remains in the asymptotically flat region. In the second scenario, the measured particle moves toward the black hole, and the quantum memories stay in the asymptotically flat region. This study considers two initial quantum states, namely GHZ and W states. Our findings reveal that in both cases, measurement uncertainty increases steadily with rising Hawking temperature. When comparing the GHZ and W states, the GHZ state initially exhibits lower measurement uncertainty at low Hawking temperatures than the W state, indicating greater resilience to Hawking radiation. Additionally, when the quantum memories remain in the asymptotically flat region while the measured particle falls toward the black hole, the uncertainties for GHZ and W states do not align at high temperatures. The GHZ state consistently demonstrates lower measurement uncertainty, showcasing its superior robustness against Hawking radiation.</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"84 11","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-024-13554-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142672636","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Kerr black hole energy extraction, irreducible mass feedback, and the effect of captured particles charge","authors":"J. A. Rueda,&nbsp;R. Ruffini","doi":"10.1140/epjc/s10052-024-13459-1","DOIUrl":"10.1140/epjc/s10052-024-13459-1","url":null,"abstract":"<div><p>We analyze the extraction of the rotational energy of a Kerr black hole (BH) endowed with a test charge and surrounded by an external test magnetic field and ionized low-density matter. For a magnetic field parallel to the BH spin, electrons move outward(inward) and protons inward(outward) in a region around the BH poles(equator). For zero charge, the polar region comprises spherical polar angles <span>(-60^circ lesssim theta lesssim 60^circ )</span> and the equatorial region <span>(60^circ lesssim theta lesssim 120^circ )</span>. The polar region shrinks for positive charge, and the equatorial region enlarges. For an isotropic particle density, we argue the BH could experience a <i>cyclic</i> behavior: starting from a zero charge, it accretes more polar protons than equatorial electrons, gaining net positive charge, energy and angular momentum. Then, the shrinking(enlarging) of the polar(equatorial) region makes it accrete more equatorial electrons than polar protons, gaining net negative charge, energy, and angular momentum. In this phase, the BH rotational energy is extracted. The extraction process continues until the new enlargement of the polar region reverses the situation, and the cycle repeats. We show that this electrodynamical process produces a relatively limited increase of the BH irreducible mass compared to gravitational mechanisms like the Penrose process, hence being a more efficient and promising mechanism for extracting the BH rotational energy.</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"84 11","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-024-13459-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142672637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamics of massive and massless particles in the spacetime of a wiggly cosmic dislocation","authors":"Frankbelson dos S. Azevedo,&nbsp;Edilberto O. Silva","doi":"10.1140/epjc/s10052-024-13572-1","DOIUrl":"10.1140/epjc/s10052-024-13572-1","url":null,"abstract":"<div><p>In this paper, we investigate the spacetime containing both small-scale structures (wiggles) and spatial dislocation, forming a wiggly cosmic dislocation. We study the combined effects of these features on the dynamics of massive and massless particles. Our results show that while wiggles alone lead to bound states and dislocation introduces angular momentum corrections, their coupling produces more complex effects, influencing both particle motion and wave propagation. Notably, this coupling significantly modifies radial solutions and eigenvalues, with the direction of motion or propagation becoming a critical factor in determining the outcomes. Numerical solutions reveal detailed aspects of particle dynamics as functions of dislocation and string parameters, including plots of trajectories, probability densities, and energy levels. These findings deepen our understanding of how a wiggly cosmic dislocation shapes particle dynamics, suggesting new directions for theoretical exploration in cosmological models.</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"84 11","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-024-13572-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142672622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring the photoproduction of (rho ) and (phi ) in hadronic heavy-ion collisions","authors":"Kaifeng Shen,&nbsp;Xin Wu,&nbsp;Zebo Tang,&nbsp;Wangmei Zha","doi":"10.1140/epjc/s10052-024-13503-0","DOIUrl":"10.1140/epjc/s10052-024-13503-0","url":null,"abstract":"<div><p>Significant enhancements of J/<span>(psi )</span> production have been observed by various experiments at RHIC and LHC for very low transverse momenta in peripheral heavy-ion collisions, which has ignited a surge of investigations into photon-induced processes in hadronic heavy-ion collisions (HHICs). Within this wave of research enthusiasm, the search for more photon induced products in HHICs becomes paramount. In this paper, we perform the calculation of the <span>(rho )</span> and <span>(phi )</span> production resulting from photon-nucleus interactions in HHICs, which are crucial probes for studying the properties of quark-gluon plasma (QGP) in HHICs. Our study reveals that, in comparison to hadronic production, the photon-induced production of <span>(rho )</span> and <span>(phi )</span> does not reach the same level of significance as that observed in J/<span>(psi )</span> production. Nevertheless, it remains substantial, especially in peripheral collisions, holding great promise for experimental verification in the imminent future.</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"84 11","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-024-13503-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142672627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermodynamics of AdS-Schwarzschild-like black hole in loop quantum gravity","authors":"Rui-Bo Wang,&nbsp;Shi-Jie Ma,&nbsp;Lei You,&nbsp;Yu-Cheng Tang,&nbsp;Yu-Hang Feng,&nbsp;Xian-Ru Hu,&nbsp;Jian-Bo Deng","doi":"10.1140/epjc/s10052-024-13505-y","DOIUrl":"10.1140/epjc/s10052-024-13505-y","url":null,"abstract":"<div><p>We obtained the metric of the Schwarzschild-like black hole with loop quantum gravity (LQG) corrections in anti-de Sitter (AdS) space-time, under the assumption that the cosmological constant is decoupled in LQG. We investigated its thermodynamics, including the equation of state, criticality, heat capacity, and Gibbs free energy. The <span>(P-v)</span> graph was plotted, and the critical behavior was calculated. It was found that, due to the LQG effect, the quantum-corrected Schwarzschild-AdS black hole exhibits a critical point and a critical ratio of 7/18, which differs from the Reissner–Nordstr<span>(ddot{textrm{o}})</span>m-AdS black hole’s ratio of 3/8 (the same as that of the Van der Waals system) slightly. However, there are still some similarities compared to the Van der Waals system, such as the same critical exponents and a similar <span>(P-v)</span> graph. Moreover, it is concluded that the energy-momentum tensor related to the black hole’s mass could violate the conventional first law of thermodynamics. This modified first law may violate the conservation of Gibbs free energy during the small black hole-large black hole phase transitions, potentially indicating the occurrence of the zeroth-order phase transition. The Joule–Thomson expansion was also studied. Interestingly, compared to the Schwarzschild-AdS black hole, the LQG effect leads to inversion points. The inversion curve divides the <span>(left( P,Tright) )</span> coordinate system into two regions: a heating region and a cooling region, as shown in detail by the inversion curves and isenthalpic curves. The results indicated that there is a minimum inversion mass, below which any black hole will not possess an inversion point.</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"84 11","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-024-13505-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664431","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing superconducting properties of YBa2Cu3O7- ẟ through Nd2O3 addition prepared using modified thermal decomposition method","authors":"Arebat Ryad Alhadei Mohamed,&nbsp;Mohd Mustafa Awang Kechik,&nbsp;Chen Soo Kien,&nbsp;Lim Kean Pah,&nbsp;Hussien Baqiah,&nbsp;Khairul Khaizi Mohd Shariff,&nbsp;Yap Siew Hong,&nbsp;Hoo Keong Peh,&nbsp;Abdul Halim Shaari,&nbsp;Syahrul Humaidi,&nbsp;Muralidhar Miryala","doi":"10.1007/s00339-024-08035-z","DOIUrl":"10.1007/s00339-024-08035-z","url":null,"abstract":"<div><p>Polycrystalline YBa₂Cu₃O_7−δ (Y-123) samples with different varying weight percentages (x = 0.0, 0.1, 0.3, 0.5, 1.0, and 5.0 wt.%) of neodymium oxide (Nd₂O₃) addition have been successfully synthesized using a modified thermal decomposition method (DM) under ambient conditions. X-ray diffraction (XRD) analysis revealed favorable orthorhombicity values (~ 0.008) for the Y-123 crystal structure, and an estimated oxygen content close to the theoretical value (~ 6.8), along with the presence of light secondary phases such as Y₂BaCuO₅ (Y-211) and BaCuO₂. For FESEM analysis, it was found that 5.0 wt.% Nd₂O₃ increased porosity and reduced grain size, negatively impacting superconductivity. Conversely, 0.5 wt.% Nd₂O₃ promoted significant grain growth, leading to enhanced grain contact and a denser microstructure. Electrical resistivity measurements confirmed superconducting transitions in all samples. Notably, the 0.5 wt.% Nd₂O₃ sample exhibited an optimal <i>T</i>_{<i>c-onset</i>} of 94.14 K with a narrow transition width Δ<i>T</i>_<i>c</i> of 4.04 K. In contrast, the higher 5.0 wt.% Nd₂O₃ concentration resulted in a broader Δ<i>T</i>_<i>c</i> of 7.47 K, suggesting the lower doping provided more optimal superconducting performance. AC susceptibility measurements corroborated these findings. This DM method offers a cost-effective approach for Y-123 synthesis, with potential for further optimization through alkali metal doping to reduce costs and environmental impact.</p></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"130 12","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664489","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ge-doping in polycrystalline GaN layer through electron beam evaporator deposition with successive ammonia annealing","authors":"N. Yusop,&nbsp;S. N. Waheeda,&nbsp;E. A. Alias,&nbsp;M. E. A. Samsudin,&nbsp;M. Ikram Md Taib,&nbsp;N. Zainal","doi":"10.1007/s00339-024-08080-8","DOIUrl":"10.1007/s00339-024-08080-8","url":null,"abstract":"<div><p>We studied the impact of Ge-doping on material properties of polycrystalline GaN layers with different Ge percentages of 2%, 5% and 10%. The carrier concentration for the undoped polycrystalline GaN layer is ~ 6 × 10¹⁹ cm^− 3, and the value increases up to ~ 1.1 × 10²¹ cm^− 3 by the Ge-doping with 5% of Ge. Meanwhile, the electron mobility is the lowest at 98.6 cm²/Vs with 5% of Ge. The result is comparable to some reported Ge-doped single crystal GaN layers with the carrier concentration of above 10²⁰ cm^− 3. Additionally, the surface of the polycrystalline GaN layer changes significantly with the Ge percentage above 5%. In particular, GaN grain protrusions and GaN grain-like rods are observed. It is found that Ge-N related compounds can form on the GaN grain-like rods. The grain protrusions and grain-like rods lead to the broadening of the Raman E₂ peak, indicating that the crystalline properties can be degraded by excessive Ge-doping.</p></div>","PeriodicalId":473,"journal":{"name":"Applied Physics A","volume":"130 12","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Is a photon ring invariably a closed structure?","authors":"Xiangyu Wang,&nbsp;Xiaobao Wang,&nbsp;Hai-Qing Zhang,&nbsp;Minyong Guo","doi":"10.1140/epjc/s10052-024-13527-6","DOIUrl":"10.1140/epjc/s10052-024-13527-6","url":null,"abstract":"<div><p>In this study, we investigate the image of a rotating compact object (CO) illuminated by a geometrically thin, optically thin disk on the equatorial plane. As the radius of the CO’s surface fluctuates, the CO may partially or entirely obscure the photon region. We observe that the perceived photon ring may exhibit discontinuities, deviating from a closed structure, and may even disappear entirely. We find that the disruption and disappearance of the photon ring are dependent on the observational angle-a novel phenomenon not previously observed in black hole imaging studies. Our study reveals that while the factors influencing this unique photon ring phenomenon are diverse and the outcomes complex, we can provide a clear and comprehensive explanation of the physical essence and variation trends of this phenomenon. We do this by introducing and analyzing the properties and interrelationships of three characteristic functions, <span>(tilde{eta })</span>, <span>(eta _o)</span>, and <span>(eta _s)</span> related to the photon impact parameters. Additionally, our analysis of the intensity cuts and inner shadows of the images uncovers patterns that differ significantly from the shadow curve.</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"84 11","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-024-13527-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142672621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Destroying the event horizon of cold dark matter-black hole system","authors":"Liping Meng,&nbsp;Zhaoyi Xu,&nbsp;Meirong Tang","doi":"10.1140/epjc/s10052-024-13524-9","DOIUrl":"10.1140/epjc/s10052-024-13524-9","url":null,"abstract":"<div><p>Since the weak cosmic censorship conjecture was proposed, research on this conjecture has been ongoing. This paper explores the conjecture in black holes that are closer to those existing in the real universe (i.e., rotating black holes enveloped by dark matter). In this paper, we obtained a first-order corrected analytical solution for the black hole event horizon through an approximate solution. The validity of the first-order corrected analytical solution will be provided in the appendix. We conduct our study by introducing a test particle and a scalar field into the black hole. Our conclusions show that, in extremal case, both a test particle and a scalar field can disrupt the event horizon of the Kerr-like black hole; in near-extremal case, both a test particle and a scalar field can disrupt the event horizon of the Kerr-like black hole. When cold dark matter is not considered, the conclusion is consistent with previous research.</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"84 11","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-024-13524-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142672625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hawking radiation at the zero temperature limit","authors":"Koray Düztaş","doi":"10.1140/epjc/s10052-024-13540-9","DOIUrl":"10.1140/epjc/s10052-024-13540-9","url":null,"abstract":"<div><p>We show that the thermal radiation derived by Hawking can be smoothly extended to the <span>(T=0)</span> limit for Kerr black holes. The emission of the modes with <span>(omega &gt; mvarOmega )</span> comes to a halt as the surface gravity vanishes. However, Kerr black holes smoothly continue to radiate both in bosonic and fermionic modes with <span>(omega &lt; mvarOmega )</span>, at the <span>(T=0)</span> limit. We derive explicit expressions for the absorption probabilities which imply that the highest rate of emission pertains to the modes with <span>(omega =(mvarOmega )/2)</span>, both for bosonic and fermionic cases. At the zero limit of thermal radiation, the number of emitted particles vanishes as <span>(omega rightarrow 0)</span>, which strictly differentiates it from the non-thermal radiation of soft particles by extremal Kerr black holes. We also note that the thermal radiation at the zero limit, drives the black hole away from extremality in accord with the third law and the cosmic censorship conjecture.</p></div>","PeriodicalId":788,"journal":{"name":"The European Physical Journal C","volume":"84 11","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epjc/s10052-024-13540-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142672638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}