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VERSION:2.0
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PRODID:UW-Madison-Physics-Events
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SEQUENCE:0
UID:UW-Physics-Event-9905
DTSTART:20261117T160000Z
DTEND:20261117T170000Z
DTSTAMP:20261113T000120Z
LAST-MODIFIED:20261110T015051Z
LOCATION:Chamberlin 3290
SUMMARY:Microscopic origin of singlet and triplet tunnel couplings for
  readout in Si/SiGe Quantum Dots\, Condensed Matter Theory Group Semin
 ar\, Minyoung Kim\, UW Madison
DESCRIPTION:Pauli spin blockade (PSB) readout in silicon quantum dots 
 relies on spin-dependent charge transitions between two-electron state
 s. While conventional descriptions often assume a single-orbital model
 \, strong electron–electron interactions\, valley degrees of freedom
 \, and alloy disorder can significantly modify the relevant tunneling 
 processes. We investigate how Wigner-molecular correlations and valley
  physics influence the singlet and triplet tunnel couplings relevant t
 o PSB readout. Using full configuration interaction\, we construct a l
 ow-energy effective Hamiltonian and extract the singlet and triplet tu
 nnel couplings and the exchange splitting at (0\,2) charge configurati
 on. We complement these numerical results with an analytical descripti
 on connecting tunneling amplitudes to spatial wavefunctions and valley
  phases and examine how alloy disorder affects these effective paramet
 ers. This framework provides a microscopic description of spin-depende
 nt tunneling beyond the conventional single-orbital model.<br>\n
URL:https://www.physics.wisc.edu/events/?id=9905
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