On-Chip Microwave Quantum Hall Circulator

Abstract

Circulators are nonreciprocal circuit elements that are integral to technologies including radar systems, microwave communication transceivers, and the readout of quantum information devices. Their nonreciprocity arises from the interference of microwaves over the centimeter scale of the signal wavelength, in the presence of bulky magnetic media that breaks time-reversal symmetry. Here, we realize a completely passive on-chip microwave circulator with size 1=1000th the wavelength by exploiting the chiral, "slow-light" response of a two-dimensional electron gas in the quantum Hall regime. For an integrated GaAs device with 330 μm diameter and about 1-GHz center frequency, a nonreciprocity of 25 dB is observed over a 50-MHz bandwidth. Furthermore, the nonreciprocity can be dynamically tuned by varying the voltage at the port, an aspect that may enable reconfigurable passive routing of microwave signals on chip.

Transmission lines and resonators based on quantum Hall plasmonics: Electromagnetic field, attenuation, and coupling to qubits

“…In this section, we present a way to model the response of a QH droplet capacitively coupled to external electrodes. A phenomenological model of these devices [8,12,15] relies on the chiral equation of motion for the EMP charge density along the edge…”

“…This approximation holds when d i L B and it allows to decouple the effects of the voltages V 1,2 (ω) applied to the top gates; the analysis of the capacitive coupling between the electrodes can be done a posteriori, see e.g. [10][11][12]15]. In this case, we obtain that well-inside R 1,2 the field V a, (1,2) (evaluated at the position of the EMP x = z = 0) is approximately homogeneous and is related to V 1,2 (ω) by V a, (1,2)…”

Anomalous Hall Coulomb drag of massive Dirac fermions

“…Drag geometries are intensively studied experimentally in Dirac fermion systems as part of the search for exciton condensation . The most promising Dirac fermion materials have been magnetic TI slabs, in which a dissipationless quantized anomalous Hall effect has been discovered [69][70][71][72], which has already been harnessed successfully [73], stimulating an intense search for device applications. The time-reversal symmetry breaking required in Hall effects [3,28,[74][75][76][77] gives Dirac fermions a finite mass and results in a non-trivial Berry curvature [3,78,79].…”

Widely Tunable On-Chip Microwave Circulator for Superconducting Quantum Circuits

“…Hall effect [12][13][14] and active devices [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30]. All of these approaches are chip based or can be adapted for chipbased implementations.…”