相关论文: Terahertz emission from mutually synchronized stan…
The Josephson effects associated with quantum tunneling of Cooper pairs manifest as nonlinear relations between the superconductivity phase difference and the bias current and voltage. Many novel phenomena appear, such as Shapiro steps in…
We have studied experimentally and numerically temperature profiles and the formation of hot spots in intrinsic Josephson junction stacks in Bi2Sr2CaCu2O8 (BSCCO). The superconducting stacks are biased in a state where all junctions are…
We fabricated small-size stacks on the surface of Bi$_2$Sr$_2$CaCu$_2$O$_{8+x}$ (BSCCO-2212) single crystals with the bulk transition temperature $T_c$$\simeq$90 K, each containing a few intrinsic Josephson junctions. Below a critical…
Josephson tunneling in twisted cuprate junctions provides a litmus test for the pairing symmetry, which is fundamental for understanding the microscopic mechanism of high temperature superconductivity. This issue is rekindled by…
The symmetry operations of the crystal groups relevant for the high temperature superconductors HgBa2CuO4+x (Hg1201), YBa2Cu3O7-x (YBCO), and Bi2Sr2CaCu2O8+x (BSCCO) are elucidated. The allowable combinations of the superconducting order…
We study the Terahertz (THz) emission mechanism in BSCCO with an external magnetic field theoretically. The total power is proportional to the square of the number of layers and the frequency. Under the small size limitation, the angular…
The nano-scale intrinsic Josephson junctions in highly anisotropic cuprate superconductors have potential for generation of terahertz electromagnetic waves. When the thickness of a superconductor sample is much smaller than the wavelength…
We calculate the angular dependence of the radiation-zone output power and electric polarization of stimulated terahertz amplified radiation (STAR) emitted from a $dc$ voltage applied across cylindrical and rectangular stacks of intrinsic…
Intrinsic Josephson-junction stacks realized in high-temperature superconductors provide a very attractive base for developing coherent sources of electromagnetic radiation in the terahertz frequency range. A promising way to synchronize…
Solving coupled nonlinear sine-Gordon equations and Maxwell equations numerically, we study the electromagnetic and superconducting properties of the single crystal of high-$T_c$ superconductor $\rm{Bi_2Sr_2CaCu_2O_{8+\delta}}$ with a…
The Bi2Sr2CaCu2O8+x high-temperature superconductor represents a natural metamaterial, composed of metallic CuO bilayers sandwiched between ionic BiO planes. Each pair of CuO bilayers forms an atomic-scale Josephson junction. Here we employ…
Superconducting materials are a key for technologies enabling a large number of devices including THz wave mixers and single photon detectors, though limited at very low temperatures for conventional superconductors. High temperature…
Li {\it et al.} [Phys. Rev. Lett. {\bf 83}, 4160 (1999)] prepared atomically clean Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ (BSCCO) Josephson junctions between identical single crystal cleaves stacked and twisted an angle $\phi_0$ about the c…
As nature junction geometry of the d-wave cuprate superconductor/insulator/the mixture of s-wave and d-wave cuprate superconductor, the upmost surface junction of intrinsic Josephson junction stack fabricated on…
Stacks of a few intrinsic tunnel junctions were micro-fabricated on the surface of Bi-2212 single crystals. The number of junctions in a stack was tailored by progressively increasing the height of the stack by ion-beam etching, while its…
We have investigated macroscopic quantum tunneling in Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ intrinsic Josephson junctions at millikelvin temperatures using microwave irradiation. Measurements show that the escape rate for uniformly switching…
Coherent terahertz (THz) emission is emerging as a powerful new tool to probe symmetry breakings in quantum materials. This method relies on second order optical nonlinearities and is complementary to second harmonic generation…
We investigate the response of a stack of intrinsic Josephson junctions (IJJs) to terahertz (THz) electromagnetic (EM) irradiation. A significant amplification of the EM wave can be achieved by the IJJs stack when the incident frequency…
Since the discovery of high temperature superconductivity in cuprates, Josephson junction based phase-sensitive experiments are believed and used to provide the most convincing evidence for determining the pairing symmetry. Regardless of…
We have measured coherent terahertz emission spectra from Bi2Sr2CaCu2O8+\delta\ mesa devices, as a function of temperature and mesa bias voltage. The emission frequency is found to be tunable by up to 12% by varying the temperature and bias…