BEGIN:VCALENDAR
VERSION:2.0
CALSCALE:GREGORIAN
PRODID:UW-Madison-Physics-Events
BEGIN:VEVENT
SEQUENCE:5
UID:UW-Physics-Event-8579
DTSTART:20240219T180000Z
DTEND:20240219T190000Z
DTSTAMP:20260413T223524Z
LAST-MODIFIED:20240205T151519Z
LOCATION:5310 Chamberlin Hall
SUMMARY:Using precision measurements to study the interplay of quantum
  mechanics and gravity and explore the universe\, Atomic Physics Semin
 ar\, Tejas Deshpande\, Northwestern University
DESCRIPTION:Gravity is the least understood of the four fundamental fo
 rces at a microscopic level. Moreover\, quantum phenomena are typicall
 y challenging to observe in macroscopic systems. An overlap between gr
 avitational and quantum phenomena is expected to occur at very high en
 ergies like those inside a black hole or close to the big bang. Precis
 ion measurements offer an alternate low-energy route to studying such 
 phenomena in tabletop experiments. Furthermore\, precision measurement
  tools can be used for cosmic exploration through detection of gravita
 tional waves (GWs) and direct detection of dark matter (DM). In this t
 alk\, I will discuss three current experiments aiming to investigate s
 uch phenomena of great importance to fundamental physics research.
\n

 \nThe first experiment involves performing light-pulse atom interferom
 etry (LPAI) over a 100 m vertical baseline and is part of an internati
 onal collaboration called Matter-wave Atomic Gradiometer Interferometr
 ic Sensor (MAGIS). I will discuss the work done by our group at Northw
 estern University (NU) on the design\, construction\, and testing of t
 he laser system for MAGIS. I will present empirical and simulation res
 ults demonstrating the potential of MAGIS to detect GWs and ultralight
  DM at mid-band frequencies (0.03-3 Hz) with unprecedented sensitivity
 . Moreover\, I will discuss how MAGIS can study macroscopic quantum ph
 enomena by creating quantum superpositions of massive systems separate
 d by tens of meters. The second experiment aims to use LPAI to measure
  Newton's gravitational constant\, to a precision of less than 10 part
 s per million\, using a 2 m vertical baseline at NU. I will present so
 me recent results from the first stage of the NU apparatus utilizing r
 esonant LPAI\, with a record 504 loops\, and discuss its implications 
 for MAGIS. The third experiment involves detecting ultralight DM using
  cryogenic Fabry-Perot cavities at NU.
\n
\nI will conclude with some 
 ideas for near-future experiments which aim to study the interplay of 
 quantum mechanics and gravity using a combination of technologies asso
 ciated with LPAI\, laser interferometry\, and kilogram-scale levitatio
 n.
\n
URL:https://www.physics.wisc.edu/events/?id=8579
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