{"id":87,"date":"2010-05-06T23:14:33","date_gmt":"2010-05-07T04:14:33","guid":{"rendered":"http:\/\/people.williams.edu\/pmajumde\/?page_id=87"},"modified":"2026-03-06T08:25:38","modified_gmt":"2026-03-06T13:25:38","slug":"our-work","status":"publish","type":"page","link":"https:\/\/sites.williams.edu\/pmajumde\/our-work\/","title":{"rendered":"Our Work"},"content":{"rendered":"

OVERVIEW — Precise measurements of atomic structure in Group III and IV atoms<\/strong><\/span><\/p>\n

A century ago, the hydrogen atom became a testing ground for the new theory of quantum mechanics.\u00a0 However, in any atomic system beyond hydrogen, approximation techniques are required for quantitative tests.\u00a0 Recently, particular heavy atomic species have become important in searching for the type of physics usually associated with accelerators and elementary particle physics.<\/p>\n

Precise, ab initio<\/em> determination of atomic wavefunctions in these complicated atoms present a significant challenge to state-of-the-art atomic theory calculations. \u00a0Yet any atomic test of elementary particle physics rely critically on accurate atomic theory, which is essential to distinguish the complicated quantum mechanics from the more \u2018fundamental\u2019 physics that is being targeted. \u00a0There is a long history of ever-improving atomic theory and corresponding precise measurements of atomic properties in the single-valence alkali systems. \u00a0In our lab we focus on the somewhat more complicated three-valence-electron systems in Group III (thallium, indium, ….), and more recently Group IV lead atoms, for which there is significantly less experimental data.<\/p>\n

Thus, at Williams, we are pursuing a series of related high-precision experiments in which semiconductor diode lasers are used to probe these multi-valence atoms. \u00a0Atomic samples are contained in heated quartz vapor cells and also in an atomic beam apparatus. \u00a0First, these experiments test the accuracy and guide the refinement of the cutting-edge atomic theory work. \u00a0Second, we can use similar techniques to design experiments that explicitly search for physics of (and beyond) the Standard Model of elementary particle physics.<\/p>\n

Our newest project focuses on demonstrating laser cooling of the lead atom for the first time.\u00a0 This work and other atomic structure measurements are underway using our lead atomic beam system, several lasers, and a new fluorescence detection \/ imaging system.\u00a0 Ultimately cold lead atoms, paired with cold atoms of gold or silver offer the exciting new possibility of searching for EDMs in new diatomic molecules.\u00a0 This work is being pursued in collaboration with the Williams group of Ben Augenbraun ’16 (former thesis student!).<\/p>\n

Key aspects of these \u2018precision measurements\u2019 include careful experimental design, laser stabilization techniques, and various sophisticated signal processing and analysis techniques, including FM spectroscopy, precision Faraday polarimetry, and lots and lots of lock-in detection.\u00a0 These measurements have been completed in collaboration with nearly 100 Williams undergraduate students as well as eight postdoctoral research associates over the past three decades.<\/p>\n

 <\/p>\n

We are grateful for the generous funding of:<\/strong><\/p>\n

\"\"<\/a><\/p>\n

NSF\/RUI program (1998 – present)<\/strong><\/h3>\n

NIST Precision Measurement Grant Program \u00a0(1999-2002)<\/strong><\/h3>\n

Research Corporation (1994-1997)<\/strong><\/h3>\n

Williams College<\/strong><\/h3>\n","protected":false},"excerpt":{"rendered":"

OVERVIEW — Precise measurements of atomic structure in Group III and IV atoms A century ago, the hydrogen atom became a testing ground for the new theory of quantum mechanics.\u00a0 However, in any atomic system beyond hydrogen, approximation techniques are … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":93,"featured_media":0,"parent":0,"menu_order":1,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_acf_changed":false,"footnotes":""},"class_list":["post-87","page","type-page","status-publish","hentry"],"acf":[],"_links":{"self":[{"href":"https:\/\/sites.williams.edu\/pmajumde\/wp-json\/wp\/v2\/pages\/87","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sites.williams.edu\/pmajumde\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/sites.williams.edu\/pmajumde\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/sites.williams.edu\/pmajumde\/wp-json\/wp\/v2\/users\/93"}],"replies":[{"embeddable":true,"href":"https:\/\/sites.williams.edu\/pmajumde\/wp-json\/wp\/v2\/comments?post=87"}],"version-history":[{"count":48,"href":"https:\/\/sites.williams.edu\/pmajumde\/wp-json\/wp\/v2\/pages\/87\/revisions"}],"predecessor-version":[{"id":950,"href":"https:\/\/sites.williams.edu\/pmajumde\/wp-json\/wp\/v2\/pages\/87\/revisions\/950"}],"wp:attachment":[{"href":"https:\/\/sites.williams.edu\/pmajumde\/wp-json\/wp\/v2\/media?parent=87"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}