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A high density source of cold, slow and rotationally pure polar molecules

Thomas Gantner, Xing Yang Wu, Manuel Koller +3 more

Bulletin of the American Physical SocietyMay 29, 20180 citations

A buffer gas beam source for short, intense and slow molecular pulses

Stefan Truppe, M. Hambach, Sarah M. Skoff +6 more

Experiments with cold molecules usually begin with a molecular source. We describe the construction and characteristics of a cryogenic buffer gas source of CaF molecules. The source emits pulses with a typical duration of 240 μs, a mean speed of about 150 m/s, and a flux of 5×1010 molecules per steradian per pulse in a single rotational state.

arXiv:1707.06291Journal of Modern OpticsNov 5, 201768 citations

Construction and Operation of a Cryogenic Source for Cold Polar Molecules

Christian Sommer

This thesis reports on the combination of buffer-gas cooling with electric velocity filtering to produce a high-density guided beam of slow and internally cold polar molecules. In the continuous source, warm molecules are first cooled by collisions with a cryogenic helium buffer gas. Cold molecules are then extracted by means of an electric quadrupole guide. For formaldehyde the population of individual rotational states in the guide is monitored by depletion spectroscopy, resulting in single-state populations up to 82 %. This thesis also reports on a technique to produce pulses of slow guided molecules. The pulses exhibit a narrow velocity distribution around a tunable velocity.This thesis reports on the combination of buffer-gas cooling with electric velocity filtering to produce a high-density guided beam of slow and internally cold polar molecules. In the continuous source, warm molecules are first cooled by collisions with a cryogenic helium buffer gas. Cold molecules are then extracted by means of an electric quadrupole guide. For formaldehyde the population of individual rotational states in the guide is monitored by depletion spectroscopy, resulting in single-state populations up to 82 %. This thesis also reports on a technique to produce pulses of slow guided molecules. The pulses exhibit a narrow velocity distribution around a tunable velocity.

Jan 1, 20110 citations

Producing Cold Molecules

Arian Jadbabaie

Springer thesesJan 1, 20250 citations

Manipulation of the motion of polyatomic molecules in the rotational ground state : microwave lens effect by AC Stark dipole force

Zhong, Wei

The main contribution of this project to the field of cold and ultracold molecules is we firstly demonstrated successful manipulation of the motion of polyatomic molecular beam in the rotational ground state, which has the lowest temperature of all possible states. Chapter 1 gives a summary of this field, including the application of cold and ultracold molecules, the methods to obtain them, and each method’s advantages and disadvantages. Once we decelerate molecular ensembles, we would like to trap the cold and ultracold molecules in electric trap, megnetic trap and megneto-optical trap. Chapter 2 starts with an introduction of the concept of supersonic beam and the basic knowledge of it, such as the specific features. The experimental setup will also be presented and explained in this chapter. The main highlight of this project is that we are manipulating molecules in the real ground state. Our molecular source is a Counter Rotating Nozzle(CRN), which can precool (or slow in alternate terminology) molecules in all states including the rotational ground state. The principle and performance of CRN will be presented and explained in Chapter 3. After obtaining a well precooled molecular beam, the microwave lens effect on various species is presented in Chapter 4. Meanwhile, the principle of AC Stark shift, AC dipole force and the microwave standing wave modes, such as TE modes and TM modes, will be explained in this chapter as well. Finally, I’ll summarize, draw conclusion of this work and describe the future expectation of this project in Chapter 5.The main contribution of this project to the field of cold and ultracold molecules is we firstly demonstrated successful manipulation of the motion of polyatomic molecular beam in the rotational ground state, which has the lowest temperature of all possible states. Chapter 1 gives a summary of this field, including the application of cold and ultracold molecules, the methods to obtain them, and each method’s advantages and disadvantages. Once we decelerate molecular ensembles, we would like to trap the cold and ultracold molecules in electric trap, megnetic trap and megneto-optical trap. Chapter 2 starts with an introduction of the concept of supersonic beam and the basic knowledge of it, such as the specific features. The experimental setup will also be presented and explained in this chapter. The main highlight of this project is that we are manipulating molecules in the real ground state. Our molecular source is a Counter Rotating Nozzle(CRN), which can precool (or slow in alternate terminology) molecules in all states including the rotational ground state. The principle and performance of CRN will be presented and explained in Chapter 3. After obtaining a well precooled molecular beam, the microwave lens effect on various species is presented in Chapter 4. Meanwhile, the principle of AC Stark shift, AC dipole force and the microwave standing wave modes, such as TE modes and TM modes, will be explained in this chapter as well. Finally, I’ll summarize, draw conclusion of this work and describe the future expectation of this project in Chapter 5.

Jan 1, 20130 citations

Cold and Slow Molecular Beam

Aug 17, 20160 citations

Pulsed Counter-Rotating Source of Slow, Cold Molecules

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