رسانش الكتروني نانو نوارهاي گرافيني در حضور اثر آهارانوف بوهم

Electronic Conductance of Graphene Nanoribbons in the Presence of Aharonov-Bohm Effect

در اﯾﻦ ﻣﻘﺎﻟﻪ ﺑﺎ اﺳﺘﻔﺎده از روش ﺗﺎﺑﻊ ﮔﺮﯾﻦ در رﻫﯿﺎﻓﺖ ﺑﺴﺘﮕﯽ ﻗﻮي و ﻫﻢﭼﻨﯿﻦ ﺗﻘﺮﯾﺐ ﻧﺰدﯾﮏﺗﺮﯾﻦ ﻫﻤﺴﺎﯾﮥ رﺳﺎﻧﺶ اﻟﮑﺘﺮوﻧﯽ ﻧﺎﻧﻮ ﻧﻮارﻫﺎي ﮔﺮاﻓﯿﻨﯽ دﺳﺘﮥ ﺻﻨﺪﻟﯽ و زﯾﮕﺰاگ ﻣﺘﺼﻞ ﺑﻪ دو ﻫﺎدي ﻓﻠﺰي در ﺣﻀﻮر ﻣﯿﺪان ﻣﻐﻨﺎﻃﯿﺴﯽ ﻣﻮﺿﻌﯽ را ﺑﺮرﺳﯽ ﻣﯽﮐﻨﯿﻢ. ﻧﺘﺎﯾﺞ ﻧﺸﺎن ﻣﯽدﻫﺪ ﮐﻪ وﺟﻮد ﺷﺎر ﻣﻐﻨﺎﻃﯿﺴﯽ در ﯾﮏ ﻧﺎﻧﻮ ﻧﻮار دﺳﺘﻪ ﺻﻨﺪﻟﯽ، ﺑﺎﻋﺚ ﮐﻮﭼﮏﺗﺮ ﺷﺪن ﮔﺎف ذاﺗﯽ ﻧﺎﻧﻮ ﻧﻮار و اﯾﺠﺎد دو ﺿﺪﺗﺸﺪﯾﺪ در ﻃﯿﻒ رﺳﺎﻧﺶ ﻣﯽﺷﻮد. در ﻣﻮردي ﮐﻪ ﺗﻤﺎم ﺣﻠﻘﻪﻫﺎ ﺣﺎوي ﺷﺎر ﻣﻐﻨﺎﻃﯿﺴﯽ ﯾﮏﻧﻮاﺧﺖ ﺑﺎﺷﻨﺪ، ﻗﺴﻤﺘﯽ از ﻧﺎﺣﯿﮥ ﺗﺸﺪﯾﺪي ﺑﻪ ﻧﺎﺣﯿﮥ ﺗﻮﻧﻞزﻧﯽ ﺗﺒﺪﯾﻞ ﺷﺪه ﮐﻪ ﻧﺸﺎندﻫﻨﺪة ﮔﺎف اﻧﺮژي ﺟﺪﯾﺪي در ﻃﯿﻒ رﺳﺎﻧﺶ اﺳﺖ. ﻫﻢﭼﻨﯿﻦ در ﯾﮏ ﻧﺎﻧﻮ ﻧﻮار زﯾﮕﺰاگ ﮐﻪ ﺑﻪﻃﻮر ﺗﺮاﻧﺲ ﺑﻪ دو ﻫﺎدي ﺳﺎده ﻣﺘﺼﻞ اﺳﺖ، در ﻏﯿﺎب ﻣﯿﺪان ﻣﻐﻨﺎﻃﯿﺴﯽ ﭼﻨﺪ ﺗﺸﺪﯾﺪ ﻓﺎﻧﻮ در ﻃﯿﻒ رﺳﺎﻧﺶ آن ﻗﺎﺑﻞ ﻣﺸﺎﻫﺪه اﺳﺖ. ﺷﺎر ﻣﻐﻨﺎﻃﯿﺴﯽ ﻣﯽﺗﻮاﻧﺪ آنﻫﺎ را از ﺑﯿﻦ ﺑﺮده و ﺿﺪﺗﺸﺪﯾﺪﻫﺎي ﺟﺪﯾﺪي اﯾﺠﺎد كند

In this paper, we study the electronic conductance of armchair and zigzag graphene nanoribbons in the presence of a local magnetic field by using Green’s function technique at the nearest neighbor tight-binding approach. The results show that the existence of magnetic flux in an armchair nanoribbon causes that the intrinsic gap of the nanoribbon becomes smaller and two anti-resonances are created in the conductance spectrum. Whenever, all rings contain the uniform magnetic flux, a part of resonance region can be converted to a tunneling region which represent a new gap energy. Moreover, in a zigzag nanoribbon which is connected to two simple leads through the trans connection, some Fano resonances can exist at the conductance spectrum in the absence of magnetic flux.