CMT Student Seminar: Anantha Rao

** This is a weekly seminar with research talks from local condensed matter theory students and postdocs, aimed at a broad quantum audience. Everyone is welcome! If you're interested in presenting at a future seminar, please send a message to This email address is being protected from spambots. You need JavaScript enabled to view it.. **
 
Time:  Thursday, March 26 - 4:00-5:00pm
Location:  ATL 3100A and Virtual Via Zoom: https://umd.zoom.us/j/94978519761
 
Speaker: Anantha Rao, UMD
Title: Interacting electrons in silicon quantum interconnects

Abstract: Coherent interconnects between gate-defined silicon quantum processing units are essential for scalable quantum computation and long-range entanglement. We argue that one-dimensional electron channels formed in the silicon quantum well of a Si/SiGe heterostructure exhibit strong Coulomb interactions and realize strongly interacting Luttinger liquid physics. At low electron densities, the system enters a Wigner regime characterized by dominant 4kF correlations; increasing the electron density leads to a crossover from the Wigner regime to a Friedel regime with dominant 2kF correlations. We support these results through large-scale density matrix renormalization group (DMRG) simulations of the interacting ground state under both screened and unscreened Coulomb potentials. We propose experimental signatures of the Wigner-Friedel crossover via charge transport and charge sensing in both zero- and high-magnetic field limits. We also analyze the impact of short-range correlated disorder - including random alloy fluctuations and valley splitting variations - and identify that the Wigner-Friedel crossover remains robust until disorder levels of about 400 micro eV. Finally, we show that the Wigner regime enables long-range capacitive coupling between quantum dots across the interconnect, suggesting a route to create long-range entanglement between solid-state qubits. Our results position silicon interconnects as a platform for studying Luttinger liquid physics and for enabling architectures supporting nonlocal quantum error correction and quantum simulation.