Current and noise suppression in ac-driven coherent transport
نویسندگان
چکیده
We investigate the possibility to manipulate for the transport through heterostructures the dc current and its noise properties by an ac gate voltage. For a computation of the noise strength, we map the system to a tight-binding model for which noise suppression by ac fields has been predicted recently. The quality of this description is tested by comparing the transmission of the tight-binding system with a transfer-matrix approach.
منابع مشابه
Transport suppression in heterostructures driven by an ac gate voltage
We explore the possibility of inducing in heterostructures driven by an ac gate voltage the coherent current suppression recently found for nanoscale conductors in oscillating fields. The destruction of current is fairly independent of the transport voltage, but can be controlled by the driving amplitude and frequency. Within a tight-binding approximation, we obtain analytical results for the a...
متن کاملCurrent noise in ac-driven nanoscale conductors.
The theory for current fluctuations in ac-driven transport through nanoscale systems is put forward. By use of a generalized, non-Hermitian Floquet theory we derive novel explicit expressions for the time-averaged current and the zero-frequency component of the power spectrum of current fluctuations. A distinct suppression of both the zero-frequency noise and the dc current occurs for suitably ...
متن کاملShot-noise control in ac-driven nanoscale conductors
We derive within a time-dependent scattering formalism expressions for both the current through ac-driven nanoscale conductors and its fluctuations. The results for the time-dependent current, its time average, and, above all, the driven shot-noise properties assume an explicit and serviceable form by relating the propagator to a non-Hermitian Floquet theory. The driven noise cannot be expresse...
متن کاملCorrelations between charge and energy current in ac-driven coherent conductors
We study transport in coherent conductors driven by a time-periodic bias voltage. We present results of the charge and energy noise and complement them by a study of the mixed noise, namely the zero-frequency correlator between charge and energy current. The mixed noise presents interference contributions and transport contributions, showing features different from those of charge and energy no...
متن کاملShot noise in a harmonically driven ballistic graphene transistor
We study time-dependent electron transport and quantum noise in a ballistic graphene field effect transistor driven by an ac gate potential. The nonlinear response to the ac signal is computed through Floquet theory for scattering states and Landauer-Büttiker theory for charge current and its fluctuations. Photon-assisted excitation of a quasibound state in the top-gate barrier leads to resonan...
متن کامل