LibGDX: move and then stop box2d immediately

I’m working on a project in LibGDX.
It’s a 2d platform game. you can say it’s like Super Mario.

So this is how i move my player to the right:

if (Gdx.input.isKeyPressed(Input.Keys.RIGHT))
    player.b2body.applyLinearImpulse(new Vector2(0.1f, 0), player.b2body.getWorldCenter(), true);
}

When i leave the key, the player is still moving a bit. (it’s still have “Linear Impulse” force on his physical body i think).

How can i make it stop?

My question could be simple as:
What is the best way to move a physical body on LibGDX in one direction while holding a key. and when i leave the key, the player stops immediately.

bdw – I have tryied with “setTransform” and it’s making issues when the body is touching other objects – plus the sahpe come “before” the rest of the game in the screen (you can see it on debug)

Thanks.