0:00:03superconducting versus a conducting electronic ground state in generality specific double wall carbon and l
0:00:09two s the authors of this paper doctor team chang and professor pinching or from
0:00:14the department of physics hong kong university of science and technology
0:00:22after the discovery of super conductivity and carbon and l two systems theoretical analysis show
0:00:28in quasi one-dimensional see entities electron film on interaction can offer to potential ground state
0:00:34super conductivity empires distorted from a conducting state
0:00:38then all the interaction between electrons becomes the deciding factor and screening of coulomb interaction
0:00:45is crucial for the appearance of super conductivity and cindy's the super conductivity behaviors usually
0:00:51a currency into bundles
0:00:53a single wall c n t is known to be some a conducting and zero
0:00:57temperature
0:00:58an interesting question is how about a single metallic double wall carbon and l two
0:01:03here we consider two of them the three any state and five zero fifteen zero
0:01:11respectively
0:01:13the inner tubes with strong electron phone on interaction to provide possibilities of electron for
0:01:19non related processes and the other tools are metallic so as to provide screening of
0:01:24coulomb interaction in the inner two
0:01:30interaction between electrons can have two components
0:01:34one is the attractive form on mediated coupling
0:01:37the other is the repulsive coulomb interaction
0:01:40we estimate the magnitude of the first one from the density function of theory and
0:01:44the second one is estimated with and without screening of the outer shell for comparison
0:01:50then we perform second order but normalisation group analysis to identify the system behaviors including
0:01:56process and the zero temperature ground state
0:02:00with a single c m t the electric lines spread over on the space
0:02:05this is the bare climb coupling without screening
0:02:08however if there is an outer metallic shell the coulomb interaction will be screen and
0:02:13its strength can be estimated with the random phase approximation
0:02:17it is about one to two order of magnitude smaller than their potential
0:02:27with for normalisation group analysis for single wall three and five zero z entities we
0:02:34get spirals distorted from a conducting ground state in agreement with all the prior theoretical
0:02:40predictions
0:02:41in the plots moving from zero to minus infinity along x-axis represents the crawling process
0:02:47approaching zero temperature
0:02:49the y-axis denotes the amplitude of different order parameters
0:02:54black lines to know charge density wave and red lines denote single super conductivity
0:03:00the charge density wave order is seem to diverge much faster than the superconducting order
0:03:05in both single wall see entities
0:03:11when the inner tubes are embedded in d w c entities results are quite different
0:03:16in both systems
0:03:18single super conductivity order exceeds charge density weight order in the closing process and this
0:03:24indicates that zero temperature ground state is superconducting
0:03:28the crossover temperature of three eight a t w c m t is extremely low
0:03:34while four five zero and fifteen zero is relatively higher
0:03:39this may be attributed to the difference in the electron film on coupling strength of
0:03:43the two systems
0:03:45the screening due to one or two greatly modifies the ground state
0:03:49this is the main result of our paper
0:03:57screening due to the outer shell of d w c m t sufficiently reduces column
0:04:01interaction between electrons
0:04:04the results g analysis shows two systems have superconducting ground state
0:04:09and broaden implication of our result is that most of the metallic d w c
0:04:13entities can become superconducting at low temperatures in agreement with the experiment